OFFSET
1,1
LINKS
Colin Barker, Table of n, a(n) for n = 1..219
Index entries for linear recurrences with constant coefficients, signature (37635,-37635,1).
FORMULA
a(n) = 37635*a(n-1)-37635*a(n-2)+a(n-3).
G.f.: -x*(x^2+3120*x+15) / ((x-1)*(x^2-37634*x+1)).
EXAMPLE
15 is in the sequence because 15 is the 3rd hexagonal number, and 3*15 is the 5th hexagonal number.
PROG
(PARI) Vec(-x*(x^2+3120*x+15)/((x-1)*(x^2-37634*x+1)) + O(x^20))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Jun 21 2015
STATUS
approved