OFFSET
1,1
COMMENTS
Also nonnegative integers y in the solutions to 15*x^2-3*y^2+21*x+y+16 = 0, the corresponding values of x being A252115.
LINKS
Colin Barker, Table of n, a(n) for n = 1..398
Index entries for linear recurrences with constant coefficients, signature (1,103682,-103682,-1,1).
FORMULA
G.f.: -x*(2*x^4+57*x^3-77605*x^2+58983*x+1283) / ((x-1)*(x^2-322*x+1)*(x^2+322*x+1)).
EXAMPLE
1283 is in the sequence because P(1283) = 2468492 = 819963+822829+825700 = H(573)+H(574)+H(575).
MATHEMATICA
LinearRecurrence[{1, 103682, -103682, -1, 1}, {1283, 60266, 133006667, 6248482130, 13790397229331}, 20] (* Harvey P. Dale, May 08 2020 *)
PROG
(PARI) Vec(-x*(2*x^4+57*x^3-77605*x^2+58983*x+1283)/((x-1)*(x^2-322*x+1)*(x^2+322*x+1)) + O(x^100))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Dec 14 2014
STATUS
approved