cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A303250 Number of nX4 0..1 arrays with every element equal to 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

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%I A303250 #4 Apr 20 2018 11:06:55
%S A303250 2,45,203,1401,8664,55624,349273,2229806,14141138,89782352,570414504,
%T A303250 3623364042,23013173083,146192778743,928659809148,5899066377892,
%U A303250 37473134952091,238043423305307,1512137758273339,9605680030690948
%N A303250 Number of nX4 0..1 arrays with every element equal to 1, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
%C A303250 Column 4 of A303254.
%H A303250 R. H. Hardin, <a href="/A303250/b303250.txt">Table of n, a(n) for n = 1..210</a>
%F A303250 Empirical: a(n) = 7*a(n-1) +7*a(n-2) -27*a(n-3) -321*a(n-4) -213*a(n-5) +2807*a(n-6) +3899*a(n-7) -8015*a(n-8) -27255*a(n-9) +12353*a(n-10) +71558*a(n-11) +3162*a(n-12) -120371*a(n-13) +8354*a(n-14) +167215*a(n-15) -138930*a(n-16) -372344*a(n-17) +512518*a(n-18) +604644*a(n-19) -441639*a(n-20) -211921*a(n-21) -765287*a(n-22) +90464*a(n-23) +299277*a(n-24) +209820*a(n-25) +1367674*a(n-26) -1121671*a(n-27) -267827*a(n-28) -130972*a(n-29) -223517*a(n-30) +827606*a(n-31) -782370*a(n-32) -82371*a(n-33) +124045*a(n-34) +68912*a(n-35) +98182*a(n-36) -75028*a(n-37) +2868*a(n-38) +4232*a(n-39) +5296*a(n-40) -864*a(n-41) -1488*a(n-42) +576*a(n-43) for n>44
%e A303250 Some solutions for n=5
%e A303250 ..0..1..0..0. .0..1..0..0. .0..0..0..0. .0..0..0..0. .0..0..1..0
%e A303250 ..1..0..1..1. .1..0..1..0. .1..1..1..0. .1..1..1..0. .1..1..0..0
%e A303250 ..1..1..0..0. .1..1..0..1. .1..0..0..0. .0..0..1..1. .1..0..0..0
%e A303250 ..0..0..0..1. .0..1..0..1. .1..0..0..0. .0..1..1..0. .0..1..1..1
%e A303250 ..1..1..1..0. .0..0..1..1. .1..1..0..0. .1..0..0..1. .1..0..0..0
%Y A303250 Cf. A303254.
%K A303250 nonn
%O A303250 1,1
%A A303250 _R. H. Hardin_, Apr 20 2018