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.

A330989 Least positive integer with exactly 2^n factorizations into factors > 1, or 0 if no such integer exists.

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%I A330989 #6 Jan 08 2020 09:45:23
%S A330989 1,4,12,0,72,0,480
%N A330989 Least positive integer with exactly 2^n factorizations into factors > 1, or 0 if no such integer exists.
%e A330989 The A001055(n) factorizations for n = 1, 4, 12, 72:
%e A330989   ()  (4)    (12)     (72)
%e A330989       (2*2)  (2*6)    (8*9)
%e A330989              (3*4)    (2*36)
%e A330989              (2*2*3)  (3*24)
%e A330989                       (4*18)
%e A330989                       (6*12)
%e A330989                       (2*4*9)
%e A330989                       (2*6*6)
%e A330989                       (3*3*8)
%e A330989                       (3*4*6)
%e A330989                       (2*2*18)
%e A330989                       (2*3*12)
%e A330989                       (2*2*2*9)
%e A330989                       (2*2*3*6)
%e A330989                       (2*3*3*4)
%e A330989                       (2*2*2*3*3)
%Y A330989 All nonzero terms belong to A025487 and also A033833.
%Y A330989 Factorizations are A001055, with image A045782.
%Y A330989 The least number with exactly n factorizations is A330973(n).
%Y A330989 Numbers whose number of factorizations is a power of 2 are A330977.
%Y A330989 The least number with exactly prime(n) factorizations is A330992(n).
%Y A330989 Cf. A002033, A045778, A045783, A318284, A330935, A330972, A330976, A330990, A330991, A331022.
%K A330989 nonn,more
%O A330989 0,2
%A A330989 _Gus Wiseman_, Jan 07 2020