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 A383514 #5 May 19 2025 09:44:14 %S A383514 10,14,15,22,26,33,34,35,38,39,46,51,55,57,58,62,65,69,74,77,82,85,86, %T A383514 87,91,93,94,95,100,106,111,115,118,119,122,123,129,130,133,134,141, %U A383514 142,143,145,146,155,158,159,161,166,170,177,178,182,183,185,187,190 %N A383514 Heinz numbers of non Wilf section-sum partitions. %C A383514 First differs from A384007 in having 1000. %C A383514 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. %C A383514 An integer partition is Wilf iff its multiplicities are all different, ranked by A130091. %C A383514 An integer partition is section-sum iff it is possible to choose a disjoint family of strict partitions, one of each of its positive 0-appended differences. These are ranked by A381432. %e A383514 The terms together with their prime indices begin: %e A383514 10: {1,3} 57: {2,8} 94: {1,15} %e A383514 14: {1,4} 58: {1,10} 95: {3,8} %e A383514 15: {2,3} 62: {1,11} 100: {1,1,3,3} %e A383514 22: {1,5} 65: {3,6} 106: {1,16} %e A383514 26: {1,6} 69: {2,9} 111: {2,12} %e A383514 33: {2,5} 74: {1,12} 115: {3,9} %e A383514 34: {1,7} 77: {4,5} 118: {1,17} %e A383514 35: {3,4} 82: {1,13} 119: {4,7} %e A383514 38: {1,8} 85: {3,7} 122: {1,18} %e A383514 39: {2,6} 86: {1,14} 123: {2,13} %e A383514 46: {1,9} 87: {2,10} 129: {2,14} %e A383514 51: {2,7} 91: {4,6} 130: {1,3,6} %e A383514 55: {3,5} 93: {2,11} 133: {4,8} %t A383514 disjointFamilies[y_]:=Select[Tuples[IntegerPartitions/@Length/@Split[y]],UnsameQ@@Join@@#&]; %t A383514 prix[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]; %t A383514 conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]]; %t A383514 Select[Range[100],disjointFamilies[conj[prix[#]]]!={}&&!UnsameQ@@Last/@FactorInteger[#]&] %Y A383514 Ranking sequences are shown in parentheses below. %Y A383514 For Look-and-Say instead of section-sum we have A351592 (A384006). %Y A383514 These partitions are counted by A383506. %Y A383514 The Look-and-Say case is A383511 (A383518). %Y A383514 For Wilf instead of non Wilf we have A383519 (A383520). %Y A383514 A055396 gives least prime index, greatest A061395. %Y A383514 A056239 adds up prime indices, row sums of A112798, counted by A001222. %Y A383514 A098859 counts Wilf partitions (A130091), conjugate (A383512). %Y A383514 A122111 represents conjugation in terms of Heinz numbers. %Y A383514 A239455 counts section-sum partitions (A381432), complement A351293 (A381433). %Y A383514 A336866 counts non Wilf partitions (A130092), conjugate (A383513). %Y A383514 A381431 is the section-sum transform. %Y A383514 A383508 counts partitions that are both Look-and-Say and section-sum (A383515). %Y A383514 A383509 counts partitions that are Look-and-Say but not section-sum (A383516). %Y A383514 A383509 counts partitions that are not Look-and-Say but are section-sum (A384007). %Y A383514 A383510 counts partitions that are neither Look-and-Say nor section-sum (A383517). %Y A383514 Cf. A000720, A001223, A048767, A051903, A212166, A320348, A325366, A325368, A383531. %K A383514 nonn %O A383514 1,1 %A A383514 _Gus Wiseman_, May 18 2025