The OEIS is supported by the many generous donors to the OEIS Foundation.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #9 Sep 18 2021 00:56:01
%S 1,4,11,17,34,35,69,70,105,106,175,142,246,213,284,284,424,321,531,
%T 428,570,535,781,572,890,750,963,858,1246,860,1425,1144,1430,1288,
%U 1716,1290,2034,1611,2004,1720,2500,1722,2751,2150,2580,2365,3289,2296,3507,2690
%N a(n) = Sum_{d|n} mu(n/d)*d*(3*d - 1)/2.
%C Previous name was: A054525 * A000326.
%F Möbius transform of the pentagonal numbers.
%F G.f.: Sum_{k>=1} mu(k) * x^k * (1 + 2*x^k) / (1 - x^k)^3. - _Ilya Gutkovskiy_, Sep 17 2021
%e a(4) = 17 = (0, -1, 0, 1) dot (1, 5, 12, 22) = (0, -5, 0, 22).
%p read("transforms") : A000326 := proc(n) n*(3*n-1)/2 ; end: a000326 := [seq(A000326(n),n=1..300)] ; a133725 := MOBIUS(a000326) ; for i from 1 to nops(a133725) do printf("%d,",op(i,a133725)) ; od: # _R. J. Mathar_, Jan 19 2009
%Y Cf. A000326, A007434, A007438, A054525.
%K nonn
%O 1,2
%A _Gary W. Adamson_, Sep 21 2007
%E More terms from _R. J. Mathar_, Jan 19 2009
%E New name from _Ilya Gutkovskiy_, Sep 17 2021