AlmostIncreasingSequence.cs

bool almostIncreasingSequence(int[] sequence) {
    
    for (int i = 0; i < sequence.Length; i++) {        
        var items = createArray(i, sequence);      
       
        if (isIncreasingSequence(items)) return true;
    }
    
    return false;
}

int[] createArray(int indexToRemove, int[] items) {
    var l = items.Length;
    var newArray = new int[items.Length -1];
    var it = 0;
    for (int j = 0; j < l; j++) {
        if (indexToRemove == j) continue;
        newArray[it] = items[j];
        it++;
    }
    return newArray;
} 

bool isIncreasingSequence(int[] items) {
    var maxIndex = items.Length -1;
    for (int j = 0; j <= maxIndex; j++) {
        var nextIndex = j + 1;
        if (nextIndex > maxIndex) break;

        var current = items[j];
        var next = items[nextIndex];
        if (next <= current) return false;            
    }
    
    return true;
}