A068043 Number of subsets of {1,2,3,...,n} that sum to 0 mod 25.

1, 1, 1, 1, 1, 1, 1, 3, 10, 23, 43, 82, 164, 328, 656, 1312, 2622, 5243, 10486, 20972, 41945, 83887, 167773, 335546, 671092, 1342184, 2684360, 5368712, 10737422, 21474842, 42949682, 85899350, 171798690, 343597388, 687194782, 1374389558

Offset

0,8

Links

Table of n, a(n) for n=0..35.

Formula

Empirical G.f.: -(x -1) * (4*x^29 +4*x^28 +4*x^27 -4*x^24 -4*x^23 -4*x^22 -3*x^21 -2*x^20 -x^19 -x^18 -x^17 -2*x^16 +4*x^15 +10*x^14 +4*x^13 -4*x^12 -6*x^11 -8*x^10 -9*x^9 -4*x^8 +2*x^7 +5*x^6 +6*x^5 +3*x^4 +2*x^3 +x^2 -1) / ((2*x -1)*(2*x^5 -1)*(2*x^25 -1)). [Colin Barker, Dec 23 2012]

Crossrefs

25th row of A068009.

Sequence in context: A172113 A172112 A227347 * A145069 A293350 A256525

Adjacent sequences: A068040 A068041 A068042 * A068044 A068045 A068046

Keyword

nonn

Author

Antti Karttunen, Feb 11 2002

Status

approved