A323627 For any nonnegative real number x, let f(x) be the real number obtained by replacing in the binary expansions of the integer and fractional parts of x each finite run of k consecutive equal bits b with a run of k-(-1)^k consecutive bits b; a(n) is the denominator of f(1/n).

1, 4, 5, 16, 3, 5, 7, 8, 17, 24, 257, 20, 129, 56, 21, 64, 9, 17, 1025, 12, 15, 257, 2047, 10, 8193, 129, 1025, 28, 10923, 21, 31, 32, 65, 72, 87381, 68, 2097153, 8200, 16383, 96, 2049, 120, 1025, 1028, 5461, 16376, 536870911, 80, 33554431, 65544, 1365, 516

Offset: 1

Author

Rémy Sigrist, Jan 20 2019

Keywords

• nonn
• frac
• base

Links

• Rémy Sigrist, PARI program for A323627

Crossrefs

See A323626 for the corresponding numerators and additional comments.

Programs

PARI

See Links section.

Formula

a(2^k) = 2^(k+1+(-1)^k) for any k >= 2.