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A166660
Totally multiplicative sequence with a(p) = 2p+1 for prime p.
2
1, 5, 7, 25, 11, 35, 15, 125, 49, 55, 23, 175, 27, 75, 77, 625, 35, 245, 39, 275, 105, 115, 47, 875, 121, 135, 343, 375, 59, 385, 63, 3125, 161, 175, 165, 1225, 75, 195, 189, 1375, 83, 525, 87, 575, 539, 235, 95, 4375, 225, 605
OFFSET
1,2
LINKS
FORMULA
Multiplicative with a(p^e) = (2p+1)^e. If n = Product p(k)^e(k) then a(n) = Product (2*p(k)+1)^e(k).
MATHEMATICA
a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((2*fi[[All, 1]] + 1)^fi[[All, 2]]) ); Table[a[n], {n, 1, 100}](* G. C. Greubel, May 21 2016 *)
CROSSREFS
Sequence in context: A025108 A298900 A357852 * A354202 A037374 A056717
KEYWORD
nonn,mult
AUTHOR
Jaroslav Krizek, Oct 18 2009
STATUS
approved