login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Number of partitions p of n such that max(p) == 2 mod 3.
1

%I #11 May 20 2024 08:57:21

%S 0,0,1,1,2,3,4,5,8,10,14,19,25,33,45,58,76,99,127,162,209,263,333,419,

%T 524,652,813,1003,1239,1524,1868,2281,2786,3382,4104,4965,5993,7213,

%U 8676,10396,12447,14866,17725,21087,25063,29711,35185,41589,49089,57839,68079

%N Number of partitions p of n such that max(p) == 2 mod 3.

%F G.f.: Sum_{k>=0} x^(3*k+2) / Product_{j=1..3*k+2} (1-x^j).

%F A000041(n) = A363045(n) + A373014(n) + a(n).

%e a(8) = 8 counts these partitions: 8, 53, 521, 5111, 2222, 22211, 221111, 2111111.

%o (PARI) my(N=60, x='x+O('x^N)); concat([0, 0], Vec(sum(k=0, N, x^(3*k+2)/prod(j=1, 3*k+2, 1-x^j))))

%Y Cf. A000041, A363045, A373014.

%K nonn

%O 0,5

%A _Seiichi Manyama_, May 20 2024