login
G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) / (1-x)^5.
0

%I #18 Sep 08 2022 08:45:46

%S 1,5,15,34,65,111,174,255,354,470,601,744,895,1049,1200,1342,1469,

%T 1575,1655,1705,1722,1705,1655,1575,1469,1342,1200,1049,895,744,601,

%U 470,354,255,174,111,65,34,15,5,1

%N G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) / (1-x)^5.

%C This is a row of the triangle in A162499.

%C Only finitely many terms are nonzero.

%p m:=5: seq(coeff(series(mul((1-x^(3*k)),k=1..m)/(1-x)^m, x,n+1),x,n),n=0..40); # _Muniru A Asiru_, Jul 07 2018

%t CoefficientList[ Series[Times @@ (1 - x^(3Range@5))/(1 - x)^5, {x, 0, 40}], x] (* _Vincenzo Librandi_, Mar 14 2013 and slightly modified by _Robert G. Wilson v_, Jul 23 2018)

%o (PARI) x='x+O('x^41); Vec((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)*(1-x^15)/(1-x)^5) \\ _G. C. Greubel_, Jul 06 2018

%o (Magma) m:=41; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)*(1-x^15)/(1-x)^5)); // _G. C. Greubel_, Jul 06 2018

%K nonn,fini,full

%O 0,2

%A _N. J. A. Sloane_, Dec 02 2009