cp's OEIS Frontend

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.

A350951 Number of odd parts minus number of odd conjugate parts in the integer partition with Heinz number n.

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%I A350951 #5 Mar 18 2022 00:20:46
%S A350951 0,0,-2,2,-2,0,-4,2,0,0,-4,0,-6,-2,0,4,-6,0,-8,0,-2,-2,-8,2,2,-4,-2,
%T A350951 -2,-10,0,-10,4,-2,-4,0,2,-12,-6,-4,2,-12,-2,-14,-2,-2,-6,-14,2,0,2,
%U A350951 -4,-4,-16,0,0,0,-6,-8,-16,2,-18,-8,-4,6,-2,-2,-18,-4,-6,0
%N A350951 Number of odd parts minus number of odd conjugate parts in the integer partition with Heinz number n.
%C A350951 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 A350951 All terms are even.
%F A350951 a(n) = A257991 - A344616(n).
%F A350951 a(A122111(n)) = -a(n), where A122111 represents partition conjugation.
%e A350951 The prime indices of 78 are (6,2,1), with conjugate (3,2,1,1,1,1), so a(78) = 1 - 5 = -4.
%t A350951 primeMS[n_]:=If[n==1,{},Flatten[Cases[FactorInteger[n],{p_,k_}:>Table[PrimePi[p],{k}]]]];
%t A350951 conj[y_]:=If[Length[y]==0,y,Table[Length[Select[y,#>=k&]],{k,1,Max[y]}]];
%t A350951 Table[Count[primeMS[n],_?OddQ]-Count[conj[primeMS[n]],_?OddQ],{n,100}]
%Y A350951 The version comparing even with odd parts is A195017.
%Y A350951 The version comparing even with odd conjugate parts is A350849.
%Y A350951 The version comparing even conjugate with odd conjugate parts is A350941.
%Y A350951 The version comparing odd with even conjugate parts is A350942.
%Y A350951 Positions of 0's are A350944, even rank case A345196, counted by A277103.
%Y A350951 The version comparing even with even conjugate parts is A350950.
%Y A350951 There are four individual statistics:
%Y A350951 - A257991 counts odd parts, conjugate A344616.
%Y A350951 - A257992 counts even parts, conjugate A350847.
%Y A350951 There are five other possible pairings of statistics:
%Y A350951 - A325698: # of even parts = # of odd parts, counted by A045931.
%Y A350951 - A349157: # of even parts = # of odd conjugate parts, counted by A277579.
%Y A350951 - A350848: # of even conj parts = # of odd conj parts, counted by A045931.
%Y A350951 - A350943: # of even conjugate parts = # of odd parts, counted by A277579.
%Y A350951 - A350945: # of even parts = # of even conjugate parts, counted by A350948.
%Y A350951 There are three possible double-pairings of statistics:
%Y A350951 - A350946, counted by A351977.
%Y A350951 - A350949, counted by A351976.
%Y A350951 - A351980, counted by A351981.
%Y A350951 The case of all four statistics equal is A350947, counted by A351978.
%Y A350951 A056239 adds up prime indices, counted by A001222, row sums of A112798.
%Y A350951 A103919 counts partitions by number of odd parts.
%Y A350951 A116482 counts partitions by number of even parts.
%Y A350951 A122111 represents partition conjugation using Heinz numbers.
%Y A350951 A316524 gives the alternating sum of prime indices.
%Y A350951 Cf. A026424, A028260, A053738, A098123, A130780, A171966, A236559, A236914, A239241, A241638, A325700.
%K A350951 sign
%O A350951 1,3
%A A350951 _Gus Wiseman_, Mar 14 2022