A232377 Number of 2Xn 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, diagonally or antidiagonally, and no adjacent values equal.
1, 14, 74, 296, 1130, 4682, 19448, 79592, 326810, 1343042, 5516132, 22658744, 93073958, 382310690, 1570402928, 6450645104, 26496901994, 108839752922, 447074397188, 1836420218672, 7543351642070, 30985365821066, 127276699845344, 522806747988728, 2147501432084138
Offset: 1
Keywords
Examples
Some solutions for n=7 ..3..0..1..2..1..0..3....0..3..2..3..0..3..0....2..1..2..3..0..3..2 ..3..2..3..0..1..0..3....2..1..0..3..2..1..0....2..3..2..3..0..1..2
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 3*a(n-1) +a(n-2) +13*a(n-3) +26*a(n-5) -4*a(n-6) +24*a(n-7) +16*a(n-8) for n>9.
Empirical g.f.: x + 2*x^2*(-7 -16*x -30*x^2 +7*x^3 -17*x^4 -30*x^5 -4*x^6 +8*x^7) / ( (2*x^2+1)*(8*x^6 +12*x^5 -6*x^4 +7*x^3 +3*x^2 +3*x-1) ). - R. J. Mathar, Nov 27 2013
Comments