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A167333 Totally multiplicative sequence with a(p) = 2*(5p-1) = 10p-2 for prime p. 1
1, 18, 28, 324, 48, 504, 68, 5832, 784, 864, 108, 9072, 128, 1224, 1344, 104976, 168, 14112, 188, 15552, 1904, 1944, 228, 163296, 2304, 2304, 21952, 22032, 288, 24192, 308, 1889568, 3024, 3024, 3264, 254016, 368, 3384, 3584, 279936, 408, 34272, 428 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..1000

FORMULA

Multiplicative with a(p^e) = (2*(5p-1))^e. If n = Product p(k)^e(k) then a(n) = Product (2*(5*p(k)-1))^e(k). a(n) = A061142(n) * A166654(n) = 2^bigomega(n) * A166654(n) = 2^A001222(n) * A166654(n).

MATHEMATICA

a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((5*fi[[All, 1]] - 1)^fi[[All, 2]])); Table[a[n]*2^PrimeOmega[n], {n, 1, 100}] (* G. C. Greubel, Jun 06 2016 *)

PROG

(PARI) a(n) = {my(f=factor(n)); for (k=1, #f~, f[k, 1] = 10*f[k, 1]-2; ); factorback(f); } \\ Michel Marcus, Jun 06 2016

CROSSREFS

Cf. A001222, A061142, A166654.

Sequence in context: A117101 A063840 A180117 * A259642 A045000 A205871

Adjacent sequences:  A167330 A167331 A167332 * A167334 A167335 A167336

KEYWORD

nonn,mult

AUTHOR

Jaroslav Krizek, Nov 01 2009

STATUS

approved

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Last modified December 5 09:47 EST 2020. Contains 338945 sequences. (Running on oeis4.)