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A322981
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If n is the k-th prime power > 1, a(n) = k, otherwise a(n) = 0.
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3
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0, 1, 2, 3, 4, 0, 5, 6, 7, 0, 8, 0, 9, 0, 0, 10, 11, 0, 12, 0, 0, 0, 13, 0, 14, 0, 15, 0, 16, 0, 17, 18, 0, 0, 0, 0, 19, 0, 0, 0, 20, 0, 21, 0, 0, 0, 22, 0, 23, 0, 0, 0, 24, 0, 0, 0, 0, 0, 25, 0, 26, 0, 0, 27, 0, 0, 28, 0, 0, 0, 29, 0, 30, 0, 0, 0, 0, 0, 31, 0, 32, 0, 33, 0, 0, 0, 0, 0, 34, 0, 0, 0, 0, 0, 0, 0, 35
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OFFSET
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1,3
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COMMENTS
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LINKS
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FORMULA
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a(A000961(1+n)) = n for all n >= 1.
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PROG
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(PARI)
up_to = 16384;
A322981list(up_to) = { my(v=vector(up_to), k=0); for(n=1, up_to, if(isprimepower(n), k++; v[n] = k, v[n] = 0)); (v); };
v322981 = A322981list(up_to);
(PARI) A322981(n)=if(isprimepower(n), sum(i=1, exponent(n), primepi(sqrtnint(n, i)))) \\ M. F. Hasler, Jun 16 2021
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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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