OFFSET
0,2
LINKS
John Machacek, A finite totally nonnegative Grassmannian, arXiv:2410.06177 [math.CO], 2024. See p. 12.
Index entries for linear recurrences with constant coefficients, signature (13,-47,35).
FORMULA
a(0)=1, a(1)=13, a(n)=12*a(n-1)-35*a(n-2)+1. - Vincenzo Librandi, Feb 10 2011
a(n) = (2*7^(n+2) - 3*5^(n+2) + 1)/24. - Yahia Kahloune, Aug 13 2013
MAPLE
a:=n->sum((7^(n-j)-5^(n-j))/2, j=0..n): seq(a(n), n=1..19); # Zerinvary Lajos, Jan 15 2007
PROG
(PARI) a(n) = (2*7^(n+2) - 3*5^(n+2) + 1)/24; \\ Joerg Arndt, Aug 13 2013
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved