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.
%I A331550 #27 Mar 29 2025 10:50:36
%S A331550 9,6,4,1,3,10,1,10,12,8,14,7,9,6,0,2,5,0,12,2,6,7,5,6,9,8,7,0,4,2,10,
%T A331550 1,2,9,8,0,11,13,6,11,6,6,12,5,2,9,0,1,5,1,10,9,11,8,8,14,0,12,6,0,1,
%U A331550 1,12,14,2,13,5,13,14,9,10,12,14,9,6,6,0,12,12,7
%N A331550 15-adic integer x = ...65762C0520697E8CA1A31469 satisfying x^3 = x.
%C A331550 The base-15 version of A091664. A, B, C, D, and E are the standard notations for the hexadecimal digits 10, 11, 12, 13, and 14, respectively. x+1 is a base-15 automorph.
%H A331550 Patrick A. Thomas, <a href="/A331550/a331550.txt">Generating Array</a>
%F A331550 x = 15-adic lim_{n->infinity} 9^(5^n).
%e A331550 x = ...65762C0520697E8CA1A31469.
%e A331550 x^2 = ...8978C2E9CE8570624D4BDA86 = A331549.
%e A331550 x^3 = ...65762C0520697E8CA1A31469 = x.
%o A331550 (PARI) \\ See A331548 with initial b=9 instead of b=3.
%o A331550 (PARI) Vecrev(digits(lift((9+O(15^99))^5^99),15)) \\ _M. F. Hasler_, Jan 26 2020
%Y A331550 Cf. A091664, A331549.
%K A331550 nonn,base
%O A331550 0,1
%A A331550 _Patrick A. Thomas_, Jan 20 2020