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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.

A329817 a(n) is the maximum number of digits that must be checked to obtain all Armstrong numbers in base n.

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%I A329817 #28 Jan 05 2025 19:51:41
%S A329817 2,7,13,20,28,35,43,52,60,69,78,87,97,106,116,126,136,146,156,167,177,
%T A329817 188,199,209,220,231,242,253,264,276,287,298,310,321,333,345,356,368,
%U A329817 380,392,404,416,428,440,452,464,476,489,501,513,526,538,551,563,576,588
%N A329817 a(n) is the maximum number of digits that must be checked to obtain all Armstrong numbers in base n.
%H A329817 Nick Hobson, <a href="/A329817/b329817.txt">Table of n, a(n) for n = 2..10000</a>
%H A329817 Nick Hobson, <a href="/A329817/a329817.c.txt">C program</a>
%H A329817 Gordon L. Miller and Mary T. Whalen, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/30-3/miller.pdf">Armstrong Numbers: 153 = 1^3 + 5^3 + 3^3</a>, Fibonacci Quarterly, 30-3 (1992), 221-224. See Table 3 p. 222.
%t A329817 a[b_] := Floor[x /. NSolve[(b-1)^x x == b^(x-1) && x>1, x, Reals][[1]]]; a /@ Range[2, 57] (* _Giovanni Resta_, Nov 22 2019 *)
%o A329817 (C) See Links section.
%Y A329817 Cf. A010343 (base 4), A010345 (base 5), A010347 (base 6), A010349 (base 7), A010351 (base 8), A010352 (base 9), A005188 (base 10).
%K A329817 nonn,base
%O A329817 2,1
%A A329817 _Michel Marcus_, Nov 22 2019
%E A329817 More terms from _Giovanni Resta_, Nov 22 2019