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A166646
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Totally multiplicative sequence with a(p) = 6*(p+1) for prime p.
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2
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1, 18, 24, 324, 36, 432, 48, 5832, 576, 648, 72, 7776, 84, 864, 864, 104976, 108, 10368, 120, 11664, 1152, 1296, 144, 139968, 1296, 1512, 13824, 15552, 180, 15552, 192, 1889568, 1728, 1944, 1728, 186624, 228, 2160, 2016, 209952, 252, 20736, 264, 23328
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OFFSET
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1,2
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LINKS
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FORMULA
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Multiplicative with a(p^e) = (6*(p+1))^e. If n = Product p(k)^e(k) then a(n) = Product (6*(p(k)+1)^e(k).
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MATHEMATICA
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a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] + 1)^fi[[All, 2]])); Table[a[n]*6^(PrimeOmega[n]), {n, 1, 100}] (* G. C. Greubel, May 20 2016 *)
f[p_, e_] := (6*(p+1))^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Oct 18 2023 *)
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PROG
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(PARI) a(n) = {my(f = factor(n)); for (k=1, #f~, f[k, 1] = 6*(f[k, 1]+1)); factorback(f); } \\ Michel Marcus, May 21 2016
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CROSSREFS
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KEYWORD
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nonn,easy,mult
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AUTHOR
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STATUS
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approved
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