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A341133
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Number of ways to write n as an ordered sum of 4 prime powers (including 1).
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8
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1, 4, 10, 20, 35, 52, 72, 96, 125, 156, 196, 236, 277, 316, 362, 400, 451, 496, 554, 604, 668, 704, 770, 808, 871, 920, 1014, 1040, 1131, 1172, 1266, 1308, 1449, 1484, 1638, 1672, 1802, 1820, 1992, 1964, 2167, 2172, 2332, 2296, 2534, 2444, 2698, 2648, 2889, 2820, 3140
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OFFSET
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4,2
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LINKS
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MAPLE
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q:= proc(n) option remember; nops(ifactors(n)[2])<2 end:
b:= proc(n, t) option remember;
`if`(n=0, `if`(t=0, 1, 0), `if`(t<1, 0, add(
`if`(q(j), b(n-j, t-1), 0), j=1..n)))
end:
a:= n-> b(n, 4):
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MATHEMATICA
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nmax = 54; CoefficientList[Series[Sum[Boole[PrimePowerQ[k] || k == 1] x^k, {k, 1, nmax}]^4, {x, 0, nmax}], x] // Drop[#, 4] &
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CROSSREFS
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Cf. A000961, A010055, A282062, A282064, A341122, A341134, A341135, A341136, A341137, A341138, A341139.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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