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.

A331385 Irregular triangle read by rows where T(n,k) is the number of integer partitions y of n such that Sum_i prime(y_i) = n + k.

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%I A331385 #6 Jan 17 2020 17:41:25
%S A331385 1,0,1,0,1,1,0,0,2,1,0,0,1,3,1,0,0,0,2,3,1,1,0,0,0,1,4,3,1,2,0,0,0,0,
%T A331385 2,5,3,2,2,0,1,0,0,0,0,1,4,6,3,4,2,0,2,0,0,0,0,0,2,6,6,4,6,2,1,2,0,1,
%U A331385 0,0,0,0,0,1,4,8,6,6,7,2,4,2,0,1,0,0,0,1
%N A331385 Irregular triangle read by rows where T(n,k) is the number of integer partitions y of n such that Sum_i prime(y_i) = n + k.
%e A331385 Triangle begins:
%e A331385   1
%e A331385   0 1
%e A331385   0 1 1
%e A331385   0 0 2 1
%e A331385   0 0 1 3 1
%e A331385   0 0 0 2 3 1 1
%e A331385   0 0 0 1 4 3 1 2
%e A331385   0 0 0 0 2 5 3 2 2 0 1
%e A331385   0 0 0 0 1 4 6 3 4 2 0 2
%e A331385   0 0 0 0 0 2 6 6 4 6 2 1 2 0 1
%e A331385   0 0 0 0 0 1 4 8 6 6 7 2 4 2 0 1 0 0 0 1
%e A331385   0 0 0 0 0 0 2 6 9 7 9 7 3 7 2 1 1 0 0 0 2
%e A331385 Row n = 8 counts the following partitions (empty column not shown):
%e A331385   (2222)  (332)    (44)      (41111)    (53)        (611)   (8)
%e A331385           (422)    (431)     (311111)   (62)        (5111)  (71)
%e A331385           (3221)   (3311)    (2111111)  (521)
%e A331385           (22211)  (4211)               (11111111)
%e A331385                    (32111)
%e A331385                    (221111)
%e A331385 Column k = 5 counts the following partitions:
%e A331385   (11111)  (411)    (43)     (332)    (3222)   (22222)
%e A331385            (3111)   (331)    (422)    (22221)
%e A331385            (21111)  (421)    (3221)
%e A331385                     (3211)   (22211)
%e A331385                     (22111)
%t A331385 Table[Length[Select[IntegerPartitions[n],Total[Prime/@#]==m&]],{n,0,10},{m,n,Max@@Table[Total[Prime/@y],{y,IntegerPartitions[n]}]}]
%Y A331385 Row lengths are A331418.
%Y A331385 Row sums are A000041.
%Y A331385 Column sums are A331387.
%Y A331385 Shifting row n to the right n times gives A331416.
%Y A331385 Partitions whose sum of primes is divisible by their sum are A331379.
%Y A331385 Partitions whose product divides their sum of primes are A331381.
%Y A331385 Partitions whose product equals their sum of primes are A331383.
%Y A331385 Cf. A000040, A001414, A014689, A056239, A330950, A330953, A330954, A331378, A331415.
%K A331385 nonn,tabf
%O A331385 0,9
%A A331385 _Gus Wiseman_, Jan 17 2020