OFFSET
1,1
COMMENTS
Row 2 of A228218.
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 10*n^2 + 4*n + 1 = A272039(n).
Conjectures from Colin Barker, Mar 16 2018: (Start)
G.f.: x*(15 + 4*x + x^2) / (1 - x)^3.
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n>3.
(End)
EXAMPLE
Some solutions for n=4:
..1....1....1....5....6....1....2...-5....8....4...-5....8....1....5...-7....0
..4....2...-3....1...-6....1....1...-1...-7....1....0...-4....5...-7....6....6
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Aug 16 2013
STATUS
approved