A268795 Number of nX5 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two exactly once.
96, 652, 3384, 23994, 168740, 1158904, 7801688, 51781418, 339641264, 2206871084, 14226779556, 91107781858, 580148670100, 3676143046622, 23194484120032, 145793482383084, 913349363853072, 5704743147188222, 35535874740219072
Offset: 1
Keywords
Examples
Some solutions for n=4 ..0..0..1..0..1. .2..2..1..2..1. .2..1..0..1..0. .0..1..0..0..0 ..1..0..1..0..0. .1..2..2..2..2. .1..0..0..0..0. .0..0..0..0..1 ..0..0..0..1..0. .1..2..2..2..1. .0..0..1..0..0. .0..1..0..0..1 ..1..0..0..0..0. .2..1..2..2..2. .1..0..0..0..0. .0..0..1..0..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A268798.
Formula
Empirical: a(n) = 2*a(n-1) +41*a(n-2) +54*a(n-3) -509*a(n-4) -2182*a(n-5) -2830*a(n-6) +1766*a(n-7) +7914*a(n-8) +2584*a(n-9) -10583*a(n-10) -6092*a(n-11) +11506*a(n-12) +5348*a(n-13) -11688*a(n-14) -620*a(n-15) +9251*a(n-16) -4462*a(n-17) -3137*a(n-18) +4774*a(n-19) -2365*a(n-20) +338*a(n-21) +198*a(n-22) -106*a(n-23) +12*a(n-24) +4*a(n-25) -a(n-26) for n>29
Comments