OFFSET
1,1
COMMENTS
Also nonnegative integers y in the solutions to 18*x^2-9*y^2+24*x-15*y+6 = 0, the corresponding values of x being A251863.
LINKS
Colin Barker, Table of n, a(n) for n = 1..653
Index entries for linear recurrences with constant coefficients, signature (1,1154,-1154,-1,1).
FORMULA
a(n) = a(n-1)+1154*a(n-2)-1154*a(n-3)-a(n-4)+a(n-5).
G.f: -x*(35*x^3+717*x^2+205*x+3) / ((x-1)*(x^2-34*x+1)*(x^2+34*x+1)).
EXAMPLE
3 is in the sequence because P(3)+P(4)+P(5) = 12+22+35 = 69 = 8+21+40 = N(2)+N(3)+N(4).
MATHEMATICA
LinearRecurrence[{1, 1154, -1154, -1, 1}, {3, 208, 4387, 240992, 5063555}, 20] (* Harvey P. Dale, Apr 29 2019 *)
PROG
(PARI) Vec(-x*(35*x^3+717*x^2+205*x+3)/((x-1)*(x^2-34*x+1)*(x^2+34*x+1)) + O(x^100))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Dec 10 2014
STATUS
approved