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 A320436 #7 Jan 08 2019 19:06:58 %S A320436 1,1,1,1,3,1,1,5,2,1,9,7,2,1,11,8,2,1,17,19,10,2,1,21,25,14,3,1,27,37, %T A320436 24,6,1,31,42,26,6,1,41,73,68,32,6,1,45,79,72,33,6,1,57,124,151,105, %U A320436 39,6,1,63,138,167,114,41,6,1,71,159,192,128,44,6,1,79 %N A320436 Irregular triangle read by rows where T(n,k) is the number of pairwise coprime k-subsets of {1,...,n}, 1 <= k <= A036234(n), where a single number is not considered to be pairwise coprime unless it is equal to 1. %e A320436 Triangle begins: %e A320436 1 %e A320436 1 1 %e A320436 1 3 1 %e A320436 1 5 2 %e A320436 1 9 7 2 %e A320436 1 11 8 2 %e A320436 1 17 19 10 2 %e A320436 1 21 25 14 3 %e A320436 1 27 37 24 6 %e A320436 1 31 42 26 6 %e A320436 1 41 73 68 32 6 %e A320436 1 45 79 72 33 6 %e A320436 1 57 124 151 105 39 6 %e A320436 1 63 138 167 114 41 6 %e A320436 1 71 159 192 128 44 6 %e A320436 1 79 183 228 157 56 8 %t A320436 Table[Length[Select[Subsets[Range[n],{k}],CoprimeQ@@#&]],{n,16},{k,PrimePi[n]+1}] %Y A320436 Except for the k = 1 column, same as A186974. %Y A320436 Row sums are A320426. %Y A320436 Second column is A015614. %Y A320436 Cf. A051424, A084422, A085945, A187106, A276187, A320423, A320430, A320435. %K A320436 nonn,tabf %O A320436 1,5 %A A320436 _Gus Wiseman_, Jan 08 2019