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.
%I A218525 #8 Jul 24 2025 19:39:48 %S A218525 256,1528,76214,1608968,49466988,1326731972,38497164700,1087736452738, %T A218525 31117471227206,886142080344254,25291550132660836,721303064302959840, %U A218525 20578939287128886034,587046975916765583280,16747555229309088955058 %N A218525 Number of 4Xn arrays of the minimum value of corresponding elements and their horizontal or antidiagonal neighbors in a random 0..3 4Xn array. %C A218525 Row 4 of A218522 %H A218525 R. H. Hardin, <a href="/A218525/b218525.txt">Table of n, a(n) for n = 1..90</a> %e A218525 Some solutions for n=3 %e A218525 ..3..1..1....1..0..0....1..1..1....3..3..3....3..0..2....0..0..1....3..0..2 %e A218525 ..3..1..2....1..0..1....3..1..2....3..3..3....0..0..0....1..2..2....0..0..1 %e A218525 ..1..0..0....0..0..3....2..2..2....3..1..0....1..0..2....3..2..2....3..0..2 %e A218525 ..1..0..3....3..0..0....2..1..1....0..0..0....1..1..1....2..1..1....0..0..2 %K A218525 nonn %O A218525 1,1 %A A218525 _R. H. Hardin_ Oct 31 2012