A302685 Number of 7Xn 0..1 arrays with every element equal to 0, 1, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
64, 22, 29, 121, 257, 1125, 6311, 25139, 96728, 439233, 1942666, 8017639, 34024545, 148137877, 632641084, 2682460593, 11495724321, 49301780598, 210361660516, 898372105583, 3844885757451, 16440103793864, 70240799575385
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0..1..0. .0..1..1..1..0. .0..1..1..1..0. .0..0..0..1..0 ..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0 ..0..1..0..1..0. .0..0..0..1..0. .0..1..0..1..0. .0..1..1..1..0 ..0..0..0..1..0. .0..1..0..1..0. .0..1..1..1..0. .0..1..0..1..0 ..0..1..0..1..0. .0..1..1..1..0. .0..1..0..1..0. .0..1..0..1..0 ..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0 ..0..1..0..0..0. .0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A302680.
Formula
Empirical: a(n) = a(n-1) +2*a(n-2) +35*a(n-3) +80*a(n-4) +23*a(n-5) -141*a(n-6) -484*a(n-7) -692*a(n-8) +387*a(n-9) -71*a(n-10) +54*a(n-11) +3416*a(n-12) +397*a(n-13) -1793*a(n-14) +2391*a(n-15) -3515*a(n-16) +596*a(n-17) +624*a(n-18) +213*a(n-19) -249*a(n-20) +2769*a(n-21) +540*a(n-22) +1022*a(n-23) +146*a(n-24) -212*a(n-25) -441*a(n-26) -128*a(n-27) +44*a(n-28) +9*a(n-29) -73*a(n-30) -6*a(n-31) for n>38
Comments