OFFSET
1,4
COMMENTS
Row 9 of A187377.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..50
FORMULA
Empirical: a(n) = 3385*n^2 - 28390*n + 56892 for n>7.
Conjectures from Colin Barker, Apr 24 2018: (Start)
G.f.: x^4*(340 + 2040*x + 2160*x^2 + 2772*x^3 - 364*x^4 + 687*x^5 - 865*x^6) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>10.
(End)
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 09 2011
STATUS
approved