A068043 - OEIS

%I #9 Feb 06 2017 14:54:23

%S 1,1,1,1,1,1,1,3,10,23,43,82,164,328,656,1312,2622,5243,10486,20972,

%T 41945,83887,167773,335546,671092,1342184,2684360,5368712,10737422,

%U 21474842,42949682,85899350,171798690,343597388,687194782,1374389558

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

%F 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]

%Y 25th row of A068009.

%K nonn

%O 0,8

%A _Antti Karttunen_, Feb 11 2002