Found myself needing this today to fix a bunch of broken ID sequences in a Rails DB that it been incorrectly restored from a backup.

fix-id-sequences.sql

DO $$
var rows = plv8.execute("select tablename, pg_get_serial_sequence(tablename, 'id') seqname from " +
  "(select tablename from pg_tables where schemaname = 'public' and tablename != 'schema_migrations') blah"
)

rows.forEach(function (row) {
    plv8.execute("select setval('" + row.seqname + "', (select max(id) from " + row.tablename + ")+1, false)")
})
$$ LANGUAGE plv8;