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A035674 Number of partitions of n into parts 8k and 8k+3 with at least one part of each type. 4

%I #17 Aug 17 2020 07:29:41

%S 0,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,1,0,3,1,0,3,1,0,3,1,6,3,1,7,3,1,7,3,

%T 12,7,3,15,7,3,16,7,21,16,7,28,16,7,31,16,36,32,16,50,32,16,57,32,60,

%U 60,32,85,61,32,100,61,98,107,61,141,110,61,169,111,157,184,111,226

%N Number of partitions of n into parts 8k and 8k+3 with at least one part of each type.

%H Robert Price, <a href="/A035674/b035674.txt">Table of n, a(n) for n = 1..1000</a>

%F G.f.: (-1 + 1/Product_{k>=0} (1 - x^(8*k + 3)))*(-1 + 1/Product_{k>=1} (1 - x^(8*k))). - _Robert Price_, Aug 12 2020

%t nmax = 78; s1 = Range[1, nmax/8]*8; s2 = Range[0, nmax/8]*8 + 3;

%t Table[Count[IntegerPartitions[n, All, s1~Join~s2],

%t x_ /; ContainsAny[x, s1 ] && ContainsAny[x, s2 ]], {n, 1, nmax}] (* _Robert Price_, Aug 12 2020 *)

%t nmax = 78; l = Rest@CoefficientList[Series[(-1 + 1/Product[(1 - x^(8 k)), {k, 1, nmax}])*(-1 + 1/Product[(1 - x^(8 k + 3)), {k, 0, nmax}]), {x, 0, nmax}], x] (* _Robert Price_, Aug 12 2020 *)

%Y Cf. A035441-A035468, A035618-A035673, A035675-A035699.

%K nonn

%O 1,19

%A _Olivier GĂ©rard_

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Last modified August 24 02:14 EDT 2024. Contains 375396 sequences. (Running on oeis4.)