A166653 Totally multiplicative sequence with a(p) = 4p-1 for prime p.

1, 7, 11, 49, 19, 77, 27, 343, 121, 133, 43, 539, 51, 189, 209, 2401, 67, 847, 75, 931, 297, 301, 91, 3773, 361, 357, 1331, 1323, 115, 1463, 123, 16807, 473, 469, 513, 5929, 147, 525, 561, 6517, 163, 2079, 171, 2107, 2299, 637, 187, 26411, 729, 2527

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Formula

Multiplicative with a(p^e) = (4p-1)^e. If n = Product p(k)^e(k) then a(n) = Product (4*p(k)-1)^e(k).

Mathematica

a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((4*fi[[All, 1]] - 1)^fi[[All, 2]])); Table[a[n], {n, 1, 100}] (* G. C. Greubel, May 21 2016 *)

Crossrefs

Sequence in context: A086828 A117392 A105867 * A057290 A003599 A018508

Adjacent sequences: A166650 A166651 A166652 * A166654 A166655 A166656

Keyword

nonn,mult

Author

Jaroslav Krizek, Oct 18 2009

Status

approved