|
%I #13 Oct 19 2023 02:17:00
%S 1,28,35,784,49,980,63,21952,1225,1372,91,27440,105,1764,1715,614656,
%T 133,34300,147,38416,2205,2548,175,768320,2401,2940,42875,49392,217,
%U 48020,231,17210368,3185,3724,3087,960400,273,4116,3675,1075648,301,61740,315,71344
%N Totally multiplicative sequence with a(p) = 7*(p+2) for prime p.
%H G. C. Greubel, <a href="/A167308/b167308.txt">Table of n, a(n) for n = 1..1000</a>
%F Multiplicative with a(p^e) = (7*(p+2))^e. If n = Product p(k)^e(k) then a(n) = Product (7*(p(k)+2))^e(k).
%F a(n) = A165828(n) * A166590(n) = 7^bigomega(n) * A166590(n) = 7^A001222(n) * A166590(n).
%t a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] + 2)^fi[[All, 2]])); Table[a[n]*7^PrimeOmega[n], {n, 1, 100}] (* _G. C. Greubel_, Jun 07 2016 *)
%t f[p_, e_] := (7*(p+2))^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* _Amiram Eldar_, Oct 19 2023 *)
%Y Cf. A001222, A165828, A166590.
%K nonn,easy,mult
%O 1,2
%A _Jaroslav Krizek_, Nov 01 2009
|
