A302227 Number of 4Xn 0..1 arrays with every element equal to 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
0, 34, 194, 934, 6110, 38736, 251254, 1610569, 10296766, 66243864, 424625879, 2726394062, 17497812841, 112298621494, 720825717366, 4626342158809, 29694255667486, 190589162278017, 1223278644711981, 7851527608519228
Offset: 1
Keywords
Examples
Some solutions for n=5 ..0..0..0..0..0. .0..1..1..1..1. .0..1..1..1..0. .0..1..1..0..0 ..1..1..1..1..0. .0..0..1..0..0. .0..0..1..0..1. .0..0..1..0..0 ..0..0..0..0..1. .1..0..1..0..0. .1..0..1..0..0. .1..0..1..0..0 ..0..1..1..1..1. .0..1..0..1..1. .1..1..0..0..0. .0..1..1..1..0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Cf. A302224.
Formula
Empirical: a(n) = 2*a(n-1) +46*a(n-2) -788*a(n-4) -646*a(n-5) +6434*a(n-6) +6201*a(n-7) -28548*a(n-8) -19144*a(n-9) +59264*a(n-10) -8209*a(n-11) +97963*a(n-12) +207006*a(n-13) -1098204*a(n-14) -507314*a(n-15) +3485081*a(n-16) +276950*a(n-17) -5506599*a(n-18) +473443*a(n-19) +2482943*a(n-20) +506556*a(n-21) +8109563*a(n-22) -4109434*a(n-23) -21303483*a(n-24) +5376215*a(n-25) +28671693*a(n-26) -135719*a(n-27) -26171138*a(n-28) -6896727*a(n-29) +15548107*a(n-30) +8991124*a(n-31) -3953690*a(n-32) -5343561*a(n-33) -1641633*a(n-34) +576769*a(n-35) +1453672*a(n-36) +1139326*a(n-37) -138815*a(n-38) -702483*a(n-39) -125657*a(n-40) +244637*a(n-41) +55357*a(n-42) -68301*a(n-43) -34287*a(n-44) +3547*a(n-45) +16186*a(n-46) +4392*a(n-47) -3502*a(n-48) -1602*a(n-49) +56*a(n-50) +268*a(n-51) +140*a(n-52) -16*a(n-53) -16*a(n-54) for n>58
Comments