A303321 Number of nX4 0..1 arrays with every element equal to 0, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1, 8, 1, 2, 4, 3, 3, 10, 9, 10, 19, 29, 40, 65, 96, 148, 238, 356, 573, 865, 1381, 2136, 3369, 5245, 8248, 12925, 20251, 31889, 49995, 78599, 123579, 194464, 305630, 481471, 757704, 1193056, 1879551, 2961524, 4666170, 7355683, 11597513, 18284922
Offset: 1
Keywords
Examples
All solutions for n=5 ..0..0..0..1. .0..1..1..1. .0..1..0..1. .0..0..1..1 ..0..0..0..1. .0..1..1..1. .0..1..0..1. .0..0..1..1 ..0..1..0..1. .0..1..0..1. .0..1..0..1. .0..1..0..1 ..0..0..0..1. .0..1..1..1. .0..1..0..1. .0..0..1..1 ..0..0..0..1. .0..1..1..1. .0..1..0..1. .0..0..1..1
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A303325.
Formula
Empirical: a(n) = 2*a(n-2) +4*a(n-3) +2*a(n-4) -3*a(n-5) -6*a(n-6) -10*a(n-7) -16*a(n-8) -9*a(n-9) +11*a(n-10) +35*a(n-11) +39*a(n-12) +30*a(n-13) +13*a(n-14) -6*a(n-15) -38*a(n-16) -66*a(n-17) -80*a(n-18) -55*a(n-19) -14*a(n-20) +25*a(n-21) +49*a(n-22) +76*a(n-23) +90*a(n-24) +67*a(n-25) +16*a(n-26) -30*a(n-27) -46*a(n-28) -37*a(n-29) -49*a(n-30) -51*a(n-31) -12*a(n-32) +47*a(n-33) +62*a(n-34) +14*a(n-35) -16*a(n-36) -7*a(n-37) -8*a(n-38) -35*a(n-39) -48*a(n-40) -18*a(n-41) +19*a(n-42) +33*a(n-43) +23*a(n-44) +16*a(n-45) +12*a(n-46) +a(n-47) -6*a(n-48) -11*a(n-49) -8*a(n-50) -3*a(n-51) -a(n-52) +2*a(n-53) +a(n-54) +a(n-55) for n>57
Comments