OFFSET
1,2
LINKS
Colin Barker, Table of n, a(n) for n = 1..875
Index entries for linear recurrences with constant coefficients, signature (1,194,-194,-1,1).
FORMULA
a(n) = a(n-1)+194*a(n-2)-194*a(n-3)-a(n-4)+a(n-5).
G.f.: -x*(x^4+4*x^3-54*x^2+4*x+1) / ((x-1)*(x^2-14*x+1)*(x^2+14*x+1)).
EXAMPLE
145 is in the sequence because it is the 10th pentagonal number and the 9th centered square number.
PROG
(PARI) Vec(-x*(x^4+4*x^3-54*x^2+4*x+1)/((x-1)*(x^2-14*x+1)*(x^2+14*x+1)) + O(x^100))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Feb 06 2015
STATUS
approved