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 A357848 #5 Oct 17 2022 07:06:57 %S A357848 1,6,15,35,40,77,84,90,143,189,210,220,221,224,250,323,364,437,462, %T A357848 490,495,504,525,528,667,748,819,858,899,988,1029,1040,1134,1147,1155, %U A357848 1188,1210,1320,1326,1375,1400,1408,1517,1564,1683,1690,1763,1904,1938,2021 %N A357848 Heinz numbers of integer partitions whose length is twice their alternating sum. %C A357848 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 A357848 The alternating sum of a sequence (y_1,...,y_k) is Sum_i (-1)^(i-1) y_i. %e A357848 The terms together with their prime indices begin: %e A357848 1: {} %e A357848 6: {1,2} %e A357848 15: {2,3} %e A357848 35: {3,4} %e A357848 40: {1,1,1,3} %e A357848 77: {4,5} %e A357848 84: {1,1,2,4} %e A357848 90: {1,2,2,3} %e A357848 143: {5,6} %e A357848 189: {2,2,2,4} %e A357848 210: {1,2,3,4} %e A357848 220: {1,1,3,5} %e A357848 221: {6,7} %e A357848 224: {1,1,1,1,1,4} %t A357848 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]]; %t A357848 sats[y_]:=Sum[(-1)^(i-Length[y])*y[[i]],{i,Length[y]}]; %t A357848 Select[Range[1000],Length[primeMS[#]]==2sats[primeMS[#]]&] %Y A357848 These partitions are counted by A357709. %Y A357848 The version for compositions is counted by A357847. %Y A357848 A000041 counts partitions, strict A000009. %Y A357848 A003963 multiplies prime indices. %Y A357848 A025047 counts alternating compositions. %Y A357848 A056239 adds up prime indices. %Y A357848 A103919 counts partitions by alternating sum, full triangle A344651. %Y A357848 A357136 counts compositions by alternating sum, full triangle A097805. %Y A357848 A357182 counts compositions w/ length = alternating sum, ranked by A357184. %Y A357848 A357189 counts partitions w/ length = alternating sum, ranked by A357486. %Y A357848 Cf. A000720, A001221, A001222, A262977, A301987, A357183, A357485, A357488. %K A357848 nonn %O A357848 1,2 %A A357848 _Gus Wiseman_, Oct 16 2022