OFFSET
1,5
COMMENTS
Row 3 of A184348
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..998
Robert Israel, Proof of formula
FORMULA
Empirical: a(n) = 2*a(n-1)-a(n-2)+a(n-81)-2*a(n-82)+a(n-83).
Coefficient of x^(81n) in h(x^(n+1))/h(x), where h(x) = (x-1)(x^16-1)(x^81-1). - Robert Israel, Nov 03 2016
EXAMPLE
All solutions for n=5
..0....1
..0....5
..5....4
MAPLE
h:= unapply((x-1)*(x^16-1)*(x^81-1), x):
f:= n -> coeff(normal(h(x^(n+1))/h(x)), x, 81*n):
map(f, [$1..100]); # Robert Israel, Nov 03 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 11 2011
STATUS
approved