OFFSET
1,1
COMMENTS
Column 4 of A250632
LINKS
R. H. Hardin, Table of n, a(n) for n = 1..210
FORMULA
Empirical: a(n) = 9*a(n-1) -30*a(n-2) +30*a(n-3) +75*a(n-4) -243*a(n-5) +152*a(n-6) +360*a(n-7) -690*a(n-8) +130*a(n-9) +780*a(n-10) -780*a(n-11) -130*a(n-12) +690*a(n-13) -360*a(n-14) -152*a(n-15) +243*a(n-16) -75*a(n-17) -30*a(n-18) +30*a(n-19) -9*a(n-20) +a(n-21) for n>24
Empirical for n mod 2 = 0: a(n) = (1/7264857600)*n^14 + (1/46126080)*n^13 + (509/319334400)*n^12 + (9587/159667200)*n^11 + (3083/2419200)*n^10 + (4243/241920)*n^9 + (81563423/406425600)*n^8 + (8764057/4838400)*n^7 + (9317323/907200)*n^6 + (34764997/725760)*n^5 + (2064044711/13305600)*n^4 + (113560957/277200)*n^3 + (871250902/1576575)*n^2 + (56045677/60060)*n + 12
Empirical for n mod 2 = 1: a(n) = (1/7264857600)*n^14 + (1/46126080)*n^13 + (509/319334400)*n^12 + (9587/159667200)*n^11 + (3083/2419200)*n^10 + (4243/241920)*n^9 + (81563423/406425600)*n^8 + (8764057/4838400)*n^7 + (9317323/907200)*n^6 + (34777093/725760)*n^5 + (2080122311/13305600)*n^4 + (905732981/2217600)*n^3 + (420887318849/807206400)*n^2 + (15772405601/15375360)*n - (250753/4096)
EXAMPLE
Some solutions for n=3
..0..1..0..1..1....0..0..0..0..0....0..0..0..0..1....0..0..0..0..1
..1..0..1..0..2....0..0..0..1..1....0..0..1..1..2....0..0..0..0..2
..0..1..0..2..2....0..0..0..1..1....1..1..2..1..2....0..0..0..0..2
..1..0..2..2..2....0..1..2..1..2....1..2..1..2..1....2..2..1..2..2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 26 2014
STATUS
approved