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.

A171606 Numbers expressible as A*B^A in two or more different ways, with A, B > 1.

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%I A171606 #15 Feb 21 2022 02:18:03
%S A171606 648,2048,4608,5184,41472,52488,472392,500000,524288,2654208,3125000,
%T A171606 4718592,10125000,13436928,21233664,30233088,46118408,76236552,
%U A171606 134217728,169869312,344373768,402653184,512000000,648000000,737894528,800000000,838860800,922640625
%N A171606 Numbers expressible as A*B^A in two or more different ways, with A, B > 1.
%C A171606 For any relatively prime pair A and C, there are infinitely many solutions A*B^A=C*D^C, with B and D of the form B=C^W*A^X, D=C^Y*A^Z, and W,Y constrained by AW=CY+1 and X,Z constrained by CZ=AX+1. Details and examples on Munafo web page.
%H A171606 Giovanni Resta, <a href="/A171606/b171606.txt">Table of n, a(n) for n = 1..10000</a>
%H A171606 R. Munafo, <a href="https://mrob.com/pub/seq/cullen.html">Generalized Cullen and Woodall Numbers</a>
%e A171606 648 = 3 * 6^3 = 2 * 18^2.
%e A171606 5184 = 4 * 6^4 = 3 * 12^3.
%e A171606 344373768 = 8 * 9^8 = 3 * 486^3 = 2 * 13122^2.
%e A171606 922640625 = 5 * 45^5 = 3 * 675^3.
%Y A171606 Cf. A171607, A235368.
%K A171606 nonn
%O A171606 1,1
%A A171606 _Robert Munafo_, Dec 12 2009
%E A171606 a(26)-a(28) from _Giovanni Resta_, Jul 12 2018