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 A357486 #6 Oct 02 2022 10:33:39 %S A357486 1,2,10,20,21,42,45,55,88,91,105,110,125,156,176,182,187,198,231,245, %T A357486 247,312,340,351,374,390,391,396,429,494,532,544,550,551,605,663,680, %U A357486 702,713,714,765,780,782,845,891,910,912,969,975,1012,1064,1073,1078 %N A357486 Heinz numbers of integer partitions with the same length as alternating sum. %C A357486 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 A357486 The alternating sum of a sequence (y_1,...,y_k) is Sum_i (-1)^(i-1) y_i. %e A357486 The terms together with their prime indices begin: %e A357486 1: {} %e A357486 2: {1} %e A357486 10: {1,3} %e A357486 20: {1,1,3} %e A357486 21: {2,4} %e A357486 42: {1,2,4} %e A357486 45: {2,2,3} %e A357486 55: {3,5} %e A357486 88: {1,1,1,5} %e A357486 91: {4,6} %e A357486 105: {2,3,4} %e A357486 110: {1,3,5} %e A357486 125: {3,3,3} %e A357486 156: {1,1,2,6} %e A357486 176: {1,1,1,1,5} %t A357486 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]; %t A357486 ats[y_]:=Sum[(-1)^(i-1)*y[[i]],{i,Length[y]}]; %t A357486 Select[Range[100],PrimeOmega[#]==ats[Reverse[primeMS[#]]]&] %Y A357486 For product instead of length we have new, counted by A004526. %Y A357486 The version for compositions is A357184, counted by A357182. %Y A357486 For absolute value we have A357486, counted by A357487. %Y A357486 These partitions are counted by A357189. %Y A357486 A000041 counts partitions, strict A000009. %Y A357486 A000712 up to 0's counts partitions, sum = twice alt sum, rank A349159. %Y A357486 A001055 counts partitions with product equal to sum, ranked by A301987. %Y A357486 A006330 up to 0's counts partitions, sum = twice rev-alt sum, rank A349160. %Y A357486 A025047 counts alternating compositions. %Y A357486 A357136 counts compositions by alternating sum. %Y A357486 Cf. A051159, A131044, A262046. %K A357486 nonn %O A357486 1,2 %A A357486 _Gus Wiseman_, Oct 01 2022