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A329817
a(n) is the maximum number of digits that must be checked to obtain all Armstrong numbers in base n.
1
2, 7, 13, 20, 28, 35, 43, 52, 60, 69, 78, 87, 97, 106, 116, 126, 136, 146, 156, 167, 177, 188, 199, 209, 220, 231, 242, 253, 264, 276, 287, 298, 310, 321, 333, 345, 356, 368, 380, 392, 404, 416, 428, 440, 452, 464, 476, 489, 501, 513, 526, 538, 551, 563, 576, 588
OFFSET
2,1
LINKS
Nick Hobson, C program
Gordon L. Miller and Mary T. Whalen, Armstrong Numbers: 153 = 1^3 + 5^3 + 3^3, Fibonacci Quarterly, 30-3 (1992), 221-224. See Table 3 p. 222.
MATHEMATICA
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 *)
PROG
(C) See Links section.
CROSSREFS
Cf. A010343 (base 4), A010345 (base 5), A010347 (base 6), A010349 (base 7), A010351 (base 8), A010352 (base 9), A005188 (base 10).
Sequence in context: A111354 A344959 A295397 * A155212 A346870 A106675
KEYWORD
nonn,base
AUTHOR
Michel Marcus, Nov 22 2019
EXTENSIONS
More terms from Giovanni Resta, Nov 22 2019
STATUS
approved