A068034 Number of subsets of {1,2,3,...,n} that sum to 0 mod 13.

1, 1, 1, 1, 1, 2, 5, 10, 20, 39, 79, 158, 316, 632, 1262, 2522, 5042, 10082, 20164, 40330, 80660, 161320, 322638, 645278, 1290556, 2581112, 5162224, 10324444, 20648884, 41297764, 82595524, 165191048, 330382100, 660764200, 1321528400

Offset

0,6

Links

Table of n, a(n) for n=0..34.

Formula

Empirical G.f.: -(2*x^13-x^10+x^9-x^6+x^4+x^3+x^2+x-1) / ((2*x-1)*(2*x^13-1)). [Colin Barker, Dec 22 2012]

Mathematica

Table[Count[Subsets[Range[n]], _?(Divisible[Total[#], 13]&)], {n, 20}] (* Harvey P. Dale, Feb 14 2012 *)

Crossrefs

13th row of A068009.

Sequence in context: A001629 A159230 A181366 * A222082 A327287 A296122

Adjacent sequences: A068031 A068032 A068033 * A068035 A068036 A068037

Keyword

nonn

Author

Antti Karttunen, Feb 11 2002

Status

approved