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 A383712 #7 May 16 2025 22:59:12 %S A383712 1,2,3,4,5,7,9,11,13,17,19,20,23,25,28,29,31,37,41,43,44,45,47,49,50, %T A383712 52,53,59,61,67,68,71,73,75,76,79,83,89,92,97,98,99,101,103,107,109, %U A383712 113,116,117,121,124,127,131,137,139,148,149,151,153,157,163,164 %N A383712 Heinz numbers of integer partitions with distinct multiplicities (Wilf) and distinct 0-appended differences. %C A383712 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 A383712 Integer partitions with distinct multiplicities are called Wilf partitions. %H A383712 Gus Wiseman, <a href="/A325325/a325325.txt">Sequences counting and ranking integer partitions by the differences of their successive parts.</a> %F A383712 Equals A130091 /\ A325367. %e A383712 The terms together with their prime indices begin: %e A383712 1: {} %e A383712 2: {1} %e A383712 3: {2} %e A383712 4: {1,1} %e A383712 5: {3} %e A383712 7: {4} %e A383712 9: {2,2} %e A383712 11: {5} %e A383712 13: {6} %e A383712 17: {7} %e A383712 19: {8} %e A383712 20: {1,1,3} %e A383712 23: {9} %e A383712 25: {3,3} %e A383712 28: {1,1,4} %e A383712 29: {10} %e A383712 31: {11} %e A383712 37: {12} %e A383712 41: {13} %e A383712 43: {14} %e A383712 44: {1,1,5} %e A383712 45: {2,2,3} %e A383712 47: {15} %e A383712 49: {4,4} %e A383712 50: {1,3,3} %t A383712 prix[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n], {p_,k_}:>Table[PrimePi[p],{k}]]]]; %t A383712 Select[Range[100],UnsameQ@@Length/@Split[prix[#]] && UnsameQ@@Differences[Append[Reverse[prix[#]],0]]&] %Y A383712 For just distinct multiplicities we have A130091 (conjugate A383512), counted by A098859. %Y A383712 For just distinct 0-appended differences we have A325367, counted by A325324. %Y A383712 These partitions are counted by A383709. %Y A383712 A000040 lists the primes, differences A001223. %Y A383712 A048767 is the Look-and-Say transform, union A351294, complement A351295. %Y A383712 A055396 gives least prime index, greatest A061395. %Y A383712 A056239 adds up prime indices, row sums of A112798, counted by A001222. %Y A383712 A122111 represents conjugation in terms of Heinz numbers. %Y A383712 A239455 counts Look-and-Say partitions, complement A351293. %Y A383712 A336866 counts non Wilf partitions, ranks A130092, conjugate A383513. %Y A383712 A383507 counts partitions that are Wilf and conjugate Wilf, ranks A383532. %Y A383712 A383530 counts partitions that are not Wilf or conjugate-Wilf, ranks A383531. %Y A383712 Cf. A000720, A005117, A047966, A238745, A320348, A325325, A325349, A325355, A325366, A325368, A325388, A383506. %K A383712 nonn %O A383712 1,2 %A A383712 _Gus Wiseman_, May 15 2025