A211206 - OEIS

A211206

Least number which reaches n under the operation introduced in A100787: first differences are the digits of the sequence.

1, 1, 3, 1, 5, 3, 7, 1, 9, 5, 5, 3, 3, 5, 3, 1, 1, 5, 3, 3, 11, 5, 1, 1, 3, 3, 5, 5, 19, 13, 1, 3, 1, 5, 7, 1, 7, 1, 7, 5, 5, 1, 13, 3, 1, 1, 11, 9, 1, 5, 3, 1, 3, 11, 1, 9, 20, 13, 3, 7, 1, 3, 5, 1, 5, 9, 3, 5, 9, 3, 11, 1, 7, 3, 11, 1, 5, 1

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OFFSET

1,3

COMMENTS

E. Angelini proposes to call Wilsonize(n) the sequence starting with n and having as first differences the digits of the (concatenated) terms of the sequence. Then this sequence lists the smallest starting value a(n)=k such that n is a term of Wilsonize(k).

LINKS

Table of n, a(n) for n=1..78.

E. Angelini, Smallest hitters, SeqFan list, Feb 04 2013

PROG

(PARI) A211206(n)={ for(k=1, n, my(seed=k, d=digits(seed)); while(seed<n, seed+=d[1]; d=vecextract(concat(d, digits(seed)), "^1")); seed==n&return(k))}

CROSSREFS

Sequence in context: A053641 A161825 A099551 * A330717 A036233 A145799

Adjacent sequences: A211203 A211204 A211205 * A211207 A211208 A211209

KEYWORD

nonn,base

AUTHOR

Eric Angelini and M. F. Hasler, Feb 04 2013

STATUS

approved