%I #28 Mar 07 2022 03:13:16

%S 1,25,3025,8281,81225,148225,670761,1030225,3186225,4447881,10962721,

%T 14402025,30525625,38452401,73188025,89397025,156975841,187279225,

%U 308880625,361722361,567440041,654592225,985646025,1122987121,1634180625,1842555625,2604979521,2911142025

%N Squares of odd square pyramidal numbers.

%H Vincenzo Librandi, <a href="/A014797/b014797.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Rec#order_13">Index entries for linear recurrences with constant coefficients</a>, signature (1,6,-6,-15,15,20,-20,-15,15,6,-6,-1,1).

%F G.f.: -(x^12 +24*x^11 +2994*x^10 +5112*x^9 +54959*x^8 +35824*x^7 +129852*x^6 +35824*x^5 +54959*x^4 +5112*x^3 +2994*x^2 +24*x +1)/((x -1)^7*(x +1)^6). - _Colin Barker_, Nov 16 2012

%F a(n) = A015221(n)^2. - _R. J. Mathar_, Jul 30 2016

%F Sum_{n>=0} 1/a(n) = (171/4 - 18*sqrt(2))*Pi^2 - 54*Pi. - _Amiram Eldar_, Mar 07 2022

%t CoefficientList[Series[-(x^12+24x^11+2994x^10+5112x^9+54959x^8+35824x^7+ 129852x^6+ 35824x^5+54959x^4+5112x^3+2994x^2+24x+1)/((x-1)^7(x+1)^6),{x,0,30}],x] (* or *) LinearRecurrence[ {1,6,-6,-15,15,20,-20,-15,15,6,-6,-1,1},{1,25,3025,8281,81225,148225,670761,1030225,3186225,4447881,10962721,14402025,30525625},30](* _Harvey P. Dale_, Feb 17 2013 *)

%Y Cf. A014798, A015221.

%K nonn,easy

%O 0,2

%A _Mohammad K. Azarian_