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 A366529 #5 Oct 16 2023 13:42:43 %S A366529 3,7,9,12,13,19,21,27,28,29,30,36,37,39,43,48,49,52,53,57,61,63,66,70, %T A366529 71,75,76,79,81,84,87,89,90,91,101,102,107,108,111,112,113,116,117, %U A366529 120,129,130,131,133,138,139,144,147,148,151,154,156,159,163,165 %N A366529 Heinz numbers of integer partitions of even numbers with at least one even part. %C A366529 The Heinz number of a partition (y_1,...,y_k) is prime(y_1)*...*prime(y_k). This gives a bijective correspondence between positive integers and integer partitions. %e A366529 The terms together with their prime indices begin: %e A366529 3: {2} %e A366529 7: {4} %e A366529 9: {2,2} %e A366529 12: {1,1,2} %e A366529 13: {6} %e A366529 19: {8} %e A366529 21: {2,4} %e A366529 27: {2,2,2} %e A366529 28: {1,1,4} %e A366529 29: {10} %e A366529 30: {1,2,3} %e A366529 36: {1,1,2,2} %e A366529 37: {12} %e A366529 39: {2,6} %e A366529 43: {14} %e A366529 48: {1,1,1,1,2} %t A366529 prix[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]; %t A366529 Select[Range[100],EvenQ[Total[prix[#]]]&&Or@@EvenQ/@prix[#]&] %Y A366529 The complement is counted by A047967. %Y A366529 For all even parts we have A066207, counted by A035363, odd A066208. %Y A366529 Not requiring an even part gives A300061. %Y A366529 For odd instead of even we have A300063. %Y A366529 Not requiring even sum gives A324929. %Y A366529 Partitions of this type are counted by A366527. %Y A366529 A112798 list prime indices, sum A056239. %Y A366529 A257991 counts odd prime indices, distinct A324966. %Y A366529 A257992 counts even prime indices, distinct A324967. %Y A366529 Cf. A000720, A001222, A003963, A033844, A086543, A324927, A358137, A366530. %K A366529 nonn %O A366529 1,1 %A A366529 _Gus Wiseman_, Oct 16 2023