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Simon Strandgaard neoneye

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neoneye / a338277_integer.rb
Last active Feb 4, 2021
Integer sequence A338277 generates a sunflower
View a338277_integer.rb
items = []
values = Array.new(1000) do |i|
n = i + 2
x = (n ** 2) / 2
y = Integer.sqrt(x)
value = x % y
items << [n, x, y, value]
value
end
IO.write('a338277_values.csv', values.join("\n"))
@neoneye
neoneye / text_plotter_example.rb
Created Jan 28, 2021
A340867 text scatter plot
View text_plotter_example.rb
def plot_modulus(values, count)
puts
s = values.map {|v| v.to_s(count) }.join('')
count.times do |i|
value = i.to_s(count)
re = Regexp.new("[^" + value + "]")
puts '# ' + s.gsub(re, ' ')
end
end
View a339699_generate_plots.rb
require 'prime'
def plot(values, modvalue)
puts
puts "plot(values, #{modvalue})"
s = values.map {|v| (v % modvalue).to_s(modvalue) }.join('')
modvalue.times do |i|
value = i.to_s(modvalue)
re = Regexp.new("[^" + value + "]")
puts '# ' + s.gsub(re, ' ')
@neoneye
neoneye / constant_to_primes.rb
Last active Nov 27, 2020
Reconstructing the primes from the Prime-Representing Constant 2.920050977316
View constant_to_primes.rb
# 2.920050977316 - A Prime-Representing Constant
# by Dylan Fridman, Juli Garbulsky, Bruno Glecer, James Grime, Massi Tron Florentin
#
# Numberphile
# https://www.youtube.com/watch?v=_gCKX6VMvmU
#
# Article
# https://arxiv.org/abs/2010.15882
#
# OEIS sequence
@neoneye
neoneye / main.rs
Last active Nov 18, 2020
Print out filename:linenumber when logging
View main.rs
use std::io::Write;
std::env::set_var("RUST_LOG", "debug");
env_logger::builder()
.format(|buf, record| {
writeln!(buf, "{} - {}:{} - {}", record.level(), record.file().unwrap_or("N/A"), record.line().unwrap_or(0), record.args())
})
.init();
@neoneye
neoneye / a136437_a338530_compare.rb
Last active Nov 1, 2020
Comparision of a136437 and a338530
View a136437_a338530_compare.rb
# Regarding
# https://oeis.org/draft/A338530
# https://oeis.org/A136437
#
# Hugo Pfoertner: Can you please check the relation to A136437? It seems that (a(n)+2)/2 = (A136437-1)/2 for the even terms after a(31).
# Hugo Pfoertner: I checked against A136437 and found a(n)=A136437(n)-3 for 31<=n<=128.
#
# Here is output of the two sequences A136437 and A338530. They are indeed the same for this range.
#
require 'prime'
View oeis_a337723_sum_with_rounding.rb
require 'prime'
PRIMES = Prime.first(1000)
# Kevin Ryde pointed out that A337724 corresponds to this formula, with crazy rounding
# prime(n) - prime(n-2)/2 + prime(n-4)/2^2 - prime(n-6)/2^3 + ...
# What about A337723, does it have a similar formula, with crazy rounding?
# Yes, I think I have found a formula that can do it.
accumulator_a = 0.5
accumulator_b = 1
View oeis_a337724_sum_with_rounding.rb
require 'prime'
PRIMES = Prime.first(1000)
# Kevin Ryde pointed out that A337724 corresponds to this formula, with crazy rounding
# prime(n) - prime(n-2)/2 + prime(n-4)/2^2 - prime(n-6)/2^3 + ...
values = [0, 1]
30.times do |i|
sum = 0
power = 0
sign = 1
@neoneye
neoneye / squareroot.rb
Created Mar 19, 2020
Alternative way of computing the squareroot using acos+sin
View squareroot.rb
# Mesolabe Compass and Square Roots - Numberphile
# https://www.youtube.com/watch?v=9VVPBS_flOI
v=4; Math.sin(Math.acos(2.0 / (v + 1) - 1.0)) * (v + 1) / 2.0
# 2.0000000000000004
v=9; Math.sin(Math.acos(2.0 / (v + 1) - 1.0)) * (v + 1) / 2.0
# 3.0
v=16; Math.sin(Math.acos(2.0 / (v + 1) - 1.0)) * (v + 1) / 2.0
@neoneye
neoneye / Logging.swift
Created Mar 29, 2019
SwiftyBeaver using Apple's unified logging system (OSLog)
View Logging.swift
// Copyright © 2019 Simon Strandgaard. All rights reserved.
import SwiftyBeaver
public let log = SwiftyBeaver.self
extension BaseDestination.LevelColor {
mutating func applyDefaultStyle() {
debug = "🏐 "
info = "🏐 "
verbose = "🏐 "