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A010349 Base-7 Armstrong or narcissistic numbers, written in base 7. 8
1, 2, 3, 4, 5, 6, 13, 34, 44, 63, 250, 251, 305, 505, 12205, 12252, 13350, 13351, 15124, 36034, 205145, 1424553, 1433554, 3126542, 4355653, 6515652, 125543055, 161340144, 254603255, 336133614, 542662326, 565264226, 13210652042, 13213641035, 13261421245, 23662020022, 52112660266 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

From M. F. Hasler, Nov 20 2019: (Start)

Like the other single-digit terms, zero would satisfy the definition (n = Sum_{i=1..k} d[i]^k where d[1..k] are the base 7 digits of n), but here only positive numbers are considered.

Whenever a(n) ends in zero (n = 11, 17, 22, 38, 57), then a(n+1) = a(n) + 1 is also a solution to the above equation. (End)

LINKS

Joseph Myers, Table of n, a(n) for n = 1..59 (the full list of terms, from Winter)

Gordon L. Miller and Mary T. Whalen, Armstrong Numbers: 153 = 1^3 + 5^3 + 3^3, Fibonacci Quarterly, 30-3 (1992), 221-224.

Eric Weisstein's World of Mathematics, Narcissistic Number

D. T. Winter, Table of Armstrong Numbers (latest backup on web.archive.org from Jan. 2010; page no longer available), published not later than Aug. 2003.

PROG

(PARI) [fromdigits(digits(n, 7))|n<-A010350] \\ M. F. Hasler, Nov 18 2019

CROSSREFS

Cf. A010350 (a(n) written in base 10).

In other bases: A010343 (base 4), A010345 (base 5), A010347 (base 6), A010351 (base 8), A010352 (base 9), A005188 (base 10).

Sequence in context: A259541 A274838 A200331 * A032995 A046063 A065638

Adjacent sequences:  A010346 A010347 A010348 * A010350 A010351 A010352

KEYWORD

base,fini,full,nonn

AUTHOR

N. J. A. Sloane

EXTENSIONS

Edited by Joseph Myers, Jun 28 2009

STATUS

approved

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Last modified May 26 14:52 EDT 2020. Contains 334626 sequences. (Running on oeis4.)