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 A212871 #6 Jul 22 2025 22:59:00 %S A212871 0,0,1,5,15,29,59,103,168,259,386,553,772,1043,1401,1832,2356,2980, %T A212871 3729,4622,5680,6872,8263,9872,11716,13767,16122,18765,21707,25010, %U A212871 28650,32686,37173,42036,47466,53375,59783,66728,74355,82632,91519,101150 %N A212871 Number of nondecreasing sequences of 4 1..n integers with no element dividing the sequence sum. %C A212871 Row 4 of A212868 %H A212871 R. H. Hardin, <a href="/A212871/b212871.txt">Table of n, a(n) for n = 1..210</a> %e A212871 Some solutions for n=8 %e A212871 ..2....3....4....3....4....3....2....4....4....2....2....3....4....2....2....2 %e A212871 ..3....3....7....5....5....3....5....4....6....3....4....5....6....2....5....5 %e A212871 ..6....5....7....7....5....4....6....5....7....4....5....5....8....3....5....5 %e A212871 ..8....5....7....7....5....7....8....6....8....8....8....6....8....4....7....5 %K A212871 nonn %O A212871 1,4 %A A212871 _R. H. Hardin_ May 29 2012