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.

A328164 Number of integer partitions of n whose unsigned differences have the same GCD as the GCD of their parts all minus 1.

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%I A328164 #5 Oct 09 2019 10:02:54
%S A328164 1,1,1,2,3,6,7,13,17,25,33,51,62,92,116,160,203,281,341,469,572,754,
%T A328164 929,1221,1466,1912,2306,2937,3548,4499,5353,6764,8062,10006,11946,
%U A328164 14764,17455,21502,25425,30949,36579,44393,52132,63042,74000,88709,104098,124448
%N A328164 Number of integer partitions of n whose unsigned differences have the same GCD as the GCD of their parts all minus 1.
%C A328164 Zeros are ignored when computing GCD, and the empty set has GCD 0.
%e A328164 The a(1) = 1 through a(8) = 17 partitions:
%e A328164   (1)  (11)  (21)   (31)    (32)     (51)      (43)       (53)
%e A328164              (111)  (211)   (41)     (321)     (61)       (71)
%e A328164                     (1111)  (221)    (411)     (322)      (332)
%e A328164                             (311)    (2211)    (331)      (431)
%e A328164                             (2111)   (3111)    (421)      (521)
%e A328164                             (11111)  (21111)   (511)      (611)
%e A328164                                      (111111)  (2221)     (3221)
%e A328164                                                (3211)     (3311)
%e A328164                                                (4111)     (4211)
%e A328164                                                (22111)    (5111)
%e A328164                                                (31111)    (22211)
%e A328164                                                (211111)   (32111)
%e A328164                                                (1111111)  (41111)
%e A328164                                                           (221111)
%e A328164                                                           (311111)
%e A328164                                                           (2111111)
%e A328164                                                           (11111111)
%t A328164 Table[Length[Select[IntegerPartitions[n],GCD@@Differences[#]==GCD@@(#-1)&]],{n,0,30}]
%Y A328164 The complement to these partitions is counted by A328163.
%Y A328164 The GCD of the divisors of n all minus 1 is A258409(n).
%Y A328164 The GCD of the prime indices of n all minus 1 is A328167(n).
%Y A328164 Partitions whose parts minus 1 are relatively prime are A328170.
%Y A328164 Cf. A000837, A018783, A175342, A279945, A289508, A328168, A328169.
%K A328164 nonn
%O A328164 0,4
%A A328164 _Gus Wiseman_, Oct 07 2019