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A325054
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Sum of all compositions [c_1, c_2, ..., c_q] of n encoded as Product_{i=1..q} prime(i)^(c_i).
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3
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1, 2, 10, 68, 640, 8372, 147820, 3321908, 90184300, 2857153892, 104146026820, 4363900557128, 209763325978480, 11462371025215112, 702793156696129600, 47649412958404240688, 3521160558576929028400, 280427910532671712997732, 23932837097476310995036900
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OFFSET
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0,2
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LINKS
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EXAMPLE
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The compositions of 3 and their encodings are [1,1,1]-> 30, [1,2]-> 18, [2,1]-> 12, [3]-> 8. The sum gives a(3) = 68.
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MAPLE
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b:= proc(n, j) option remember; `if`(n=0, 1,
add(ithprime(j)^i*b(n-i, j+1), i=1..n))
end:
a:= n-> b(n, 1):
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MATHEMATICA
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b[n_, j_] := b[n, j] = If[n==0, 1, Sum[Prime[j]^i*b[n-i, j+1], {i, 1, n}]];
a[n_] := b[n, 1];
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CROSSREFS
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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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