A122618 - OEIS

A122618

a(n) = n_n, where "N_b" denotes "N read in base b": if N = Sum c_i 10^i then N_b = Sum c_i b^i.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 40, 43, 46, 49, 52, 55, 58, 61, 64, 67, 90, 94, 98, 102, 106, 110, 114, 118, 122, 126, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 250, 256, 262, 268, 274, 280, 286, 292, 298, 304, 360, 367, 374, 381, 388

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

The definition applies even if b < 10. Examples: 23_45 = 2*45 + 3 = 93, 23_2 = 2*2 + 3 = 7.

REFERENCES

David Applegate, Marc LeBrun and N. J. A. Sloane, Descending Dungeons and Iterated Base-Changing, in "The Mathematics of Preference, Choice and Order: Essays in Honor of Peter Fishburn", edited by Steven Brams, William V. Gehrlein and Fred S. Roberts, Springer, 2009, pp. 393-402.

LINKS

N. J. A. Sloane, Table of n, a(n) for n = 1..10000

David Applegate, Marc LeBrun and N. J. A. Sloane, Descending Dungeons and Iterated Base-Changing, arXiv:math/0611293 [math.NT], 2006-2007.

David Applegate, Marc LeBrun, N. J. A. Sloane, Descending Dungeons, Problem 11286, Amer. Math. Monthly, 116 (2009) 466-467.

MAPLE

A122618 := proc(n)

local dgs;

dgs := convert(n, base, 10) ;

add(op(i, dgs)*n^(i-1), i=1..nops(dgs)) ;

end proc: # R. J. Mathar, May 06 2019

MATHEMATICA

f[n_] := FromDigits[ IntegerDigits@n, n]; Array[f, 64] (* Robert G. Wilson v, Sep 27 2006 *)

PROG

(PARI) A122618(n, d=digits(n))=d*vectorv(#d, i, n^(#d-i)) \\ M. F. Hasler, Apr 22 2015

CROSSREFS

Differs from A083292 starting at n=100.

Cf. A028897 (n_2), A122640 (2n_2).

Sequence in context: A008728 A179052 A083292 * A033062 A060472 A130514

Adjacent sequences: A122615 A122616 A122617 * A122619 A122620 A122621

KEYWORD

nonn,base,easy

AUTHOR

N. J. A. Sloane, Sep 21 2006

STATUS

approved