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A302312
Number of 4Xn 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
8, 10, 33, 66, 194, 663, 2048, 5790, 17761, 58980, 191180, 596347, 1907378, 6288532, 20577053, 66405860, 215990588, 709815637, 2327287890, 7595046870, 24844917677, 81549601926, 267490606860, 876047158691, 2871110160412, 9420069102786
OFFSET
1,1
COMMENTS
Row 4 of A302309.
LINKS
FORMULA
Empirical: a(n) = 2*a(n-1) +5*a(n-2) +60*a(n-4) -131*a(n-5) -353*a(n-6) +10*a(n-7) -1175*a(n-8) +3055*a(n-9) +7872*a(n-10) +147*a(n-11) +12947*a(n-12) -33227*a(n-13) -87331*a(n-14) -9250*a(n-15) -93900*a(n-16) +187065*a(n-17) +567276*a(n-18) +117942*a(n-19) +450056*a(n-20) -548959*a(n-21) -2334141*a(n-22) -730683*a(n-23) -1443723*a(n-24) +687058*a(n-25) +6323246*a(n-26) +2755222*a(n-27) +3362249*a(n-28) +657022*a(n-29) -11137465*a(n-30) -6733801*a(n-31) -5922943*a(n-32) -4829865*a(n-33) +11295211*a(n-34) +9594872*a(n-35) +7037564*a(n-36) +9773770*a(n-37) -4045646*a(n-38) -6292677*a(n-39) -2960406*a(n-40) -7716783*a(n-41) -3109708*a(n-42) +290519*a(n-43) -336302*a(n-44) +1567545*a(n-45) +1178128*a(n-46) +451089*a(n-47) +464276*a(n-48) -213008*a(n-49) -10214*a(n-50) -148486*a(n-51) -128582*a(n-52) +12396*a(n-53) -23456*a(n-54) +25976*a(n-55) +10232*a(n-56) -212*a(n-57) +1968*a(n-58) -1008*a(n-59) -160*a(n-60) +64*a(n-61) for n>64
EXAMPLE
Some solutions for n=5
..0..1..0..0..1. .0..1..0..1..0. .0..0..1..0..1. .0..1..1..1..0
..1..1..0..1..0. .1..1..0..1..0. .1..1..1..0..1. .1..1..1..0..1
..0..1..0..1..0. .0..1..0..1..1. .0..0..0..0..1. .0..1..1..0..1
..0..0..0..1..0. .0..0..0..1..0. .0..1..1..0..1. .0..1..0..1..1
CROSSREFS
Cf. A302309.
Sequence in context: A126807 A230110 A223587 * A245199 A303042 A242506
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 05 2018
STATUS
approved