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.

A372890 Sum of binary ranks of all integer partitions of n, where the binary rank of a partition y is given by Sum_i 2^(y_i-1).

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%I A372890 #15 May 24 2024 14:30:29
%S A372890 0,1,4,10,25,52,115,228,471,931,1871,3687,7373,14572,29049,57694,
%T A372890 115058,229101,457392,912469,1822945,3640998,7277426,14544436,
%U A372890 29079423,58137188,116254386,232465342,464889800,929691662,1859302291,3718428513,7436694889,14873042016
%N A372890 Sum of binary ranks of all integer partitions of n, where the binary rank of a partition y is given by Sum_i 2^(y_i-1).
%H A372890 Alois P. Heinz, <a href="/A372890/b372890.txt">Table of n, a(n) for n = 0..3321</a>
%F A372890 From _Alois P. Heinz_, May 23 2024: (Start)
%F A372890 a(n) = Sum_{k=1..n} 2^(k-1) * A066633(n,k).
%F A372890 a(n) mod 2 = A365410(n-1) for n>=1. (End)
%e A372890 The partitions of 4 are (4), (3,1), (2,2), (2,1,1), (1,1,1,1), with respective binary ranks 8, 5, 4, 4, 4 with sum 25, so a(4) = 25.
%p A372890 b:= proc(n, i) option remember; `if`(n=0 or i=1, [1, n],
%p A372890       b(n, i-1)+(p->[0, p[1]*2^(i-1)]+p)(b(n-i, min(n-i, i))))
%p A372890     end:
%p A372890 a:= n-> b(n$2)[2]:
%p A372890 seq(a(n), n=0..33);  # _Alois P. Heinz_, May 23 2024
%t A372890 Table[Total[Total[2^(#-1)]&/@IntegerPartitions[n]],{n,0,10}]
%Y A372890 For Heinz number (not binary rank) we have A145519, row sums of A215366.
%Y A372890 For Heinz number the strict version is A147655, row sums of A246867.
%Y A372890 The strict version is A372888, row sums of A118462.
%Y A372890 A005117 gives Heinz numbers of strict integer partitions.
%Y A372890 A048675 gives binary rank of prime indices, distinct A087207.
%Y A372890 A061395 gives greatest prime index, least A055396.
%Y A372890 A118457 lists strict partitions in Mathematica order.
%Y A372890 A277905 groups all positive integers by binary rank of prime indices.
%Y A372890 Binary indices (A048793):
%Y A372890 - length A000120, complement A023416
%Y A372890 - min A001511, opposite A000012
%Y A372890 - max A029837 or A070939, opposite A070940
%Y A372890 - sum A029931, product A096111
%Y A372890 - reverse A272020
%Y A372890 - complement A368494, sum A359400
%Y A372890 - opposite complement A371571, sum A359359
%Y A372890 - opposite A371572, sum A230877
%Y A372890 Cf. A000041, A005940, A018819, A019565, A066633, A225620, A344086, A365410.
%K A372890 nonn
%O A372890 0,3
%A A372890 _Gus Wiseman_, May 23 2024