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Number of ways to write n as an ordered sum of 8 prime powers (including 1).
7

%I #6 Feb 05 2021 18:53:33

%S 1,8,36,120,330,784,1660,3208,5763,9752,15724,24368,36520,53152,75392,

%T 104464,141717,188624,246836,318088,404356,507656,630172,774048,

%U 941685,1135304,1357652,1611240,1899138,2224016,2589352,2997544,3452619,3957480,4516912,5134096,5815338

%N Number of ways to write n as an ordered sum of 8 prime powers (including 1).

%p q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:

%p b:= proc(n, t) option remember;

%p `if`(n=0, `if`(t=0, 1, 0), `if`(t<1, 0, add(

%p `if`(q(j), b(n-j, t-1), 0), j=1..n)))

%p end:

%p a:= n-> b(n, 8):

%p seq(a(n), n=8..44); # _Alois P. Heinz_, Feb 05 2021

%t nmax = 44; CoefficientList[Series[Sum[Boole[PrimePowerQ[k] || k == 1] x^k, {k, 1, nmax}]^8, {x, 0, nmax}], x] // Drop[#, 8] &

%Y Cf. A000961, A010055, A282062, A282064, A341126, A341133, A341134, A341135, A341136, A341138, A341139.

%K nonn

%O 8,2

%A _Ilya Gutkovskiy_, Feb 05 2021