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A107408 Form the sum of the digits of a(n); a(n+1) is the smallest unused integer having a copy of every digit of this sum. 1
0, 10, 1, 11, 2, 12, 3, 13, 4, 14, 5, 15, 6, 16, 7, 17, 8, 18, 9, 19, 100, 21, 23, 25, 27, 29, 101, 20, 22, 24, 26, 28, 102, 30, 31, 34, 37, 103, 40, 41, 35, 38, 110, 32, 45, 39, 112, 42, 36, 49, 113, 50, 51, 46, 104, 52, 47, 111, 33, 56, 114, 60, 61, 57, 120, 43, 67, 123, 62 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

The "seed" is 0 in this case.

This is a permutation of the nonnegative integers. - Nadia Heninger, Aug 10 2005

LINKS

R. J. Mathar, Feb 21 2008, Table of n, a(n) for n = 0..93

N. Heninger, E. M. Rains and N. J. A. Sloane, On the Integrality of n-th Roots of Generating Functions, J. Combinatorial Theory, Series A, 113 (2006), 1732-1745.

EXAMPLE

Sum of the digits of 29 is 11; the smallest available integer which has a copy of every digit of 11 is 101 (not 31).

MAPLE

A007953 := proc(n) add(i, i=convert(n, base, 10)) ; end: multDigs := proc(n) local a, dgs, i; if n = 0 then a := [1, seq(0, i=1..9)] ; else a := [seq(0, i=0..9)] ; dgs := convert(n, base, 10) ; for i in dgs do a := subsop(i+1=op(i+1, a)+1, a) ; od: fi ; RETURN(a) ; end: A107408 := proc(nmax) local a, ds, dsk, k, works, d ; a := [0] ; while nops(a) < nmax do ds := multDigs(A007953(op(-1, a))) ; for k from 1 do if not k in a then dsk := multDigs(k) ; works := true; for d from 1 to 10 do if op(d, dsk) < op(d, ds) then works := false ; break ; fi ; od: if works then a := [op(a), k] ; break ; fi ; fi ; od: od: RETURN(a) ; end: A107408(120) ; # R. J. Mathar, Feb 21 2008

CROSSREFS

Sequence in context: A238880 A130858 A098760 * A129888 A239113 A107353

Adjacent sequences:  A107405 A107406 A107407 * A107409 A107410 A107411

KEYWORD

base,easy,nonn

AUTHOR

Eric Angelini, Jun 09 2005

EXTENSIONS

Corrected and extended by R. J. Mathar, Feb 21 2008

STATUS

approved

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Last modified December 3 21:14 EST 2016. Contains 278745 sequences.