A078610 Least m such that B(n!) = B(n!+m), where B(n) is the sum of binary digits of n.

1, 2, 3, 9, 15, 16, 17, 129, 129, 271, 256, 1055, 1025, 2048, 2049, 32769, 32769, 65537, 65536, 262144, 262144, 524289, 524288, 4194307, 4194311, 8388609, 8388608, 33554435, 33554433, 67108864, 67108865, 2147483649, 2147483649, 4294967297

Offset

1,2

Links

Table of n, a(n) for n=1..34.

Example

a(6)=16 because 6! = [1, 0, 1, 1, 0, 1, 0, 0, 0, 0] and 6!+16 = [1, 0, 1, 1, 1, 0, 0, 0, 0, 0].

Prog

(PARI) a(n) = {s = norml2(binary(n!)); m = 1; while (norml2(binary(m+n!)) != s, m++); return (m); } \\ Michel Marcus, Jun 28 2013
(PARI) a(n)=my(N=n!, h=hammingweight(N), m); while(hammingweight(N+m++)!=h, ); m \\ Charles R Greathouse IV, Jun 28 2013

Crossrefs

Cf. A000120.

Sequence in context: A368567 A083303 A245594 * A108825 A109663 A056702

Adjacent sequences: A078607 A078608 A078609 * A078611 A078612 A078613

Keyword

nonn,base

Author

Jason Earls, Dec 09 2002

Extensions

More terms from Sascha Kurz, Jan 04 2003

Status

approved