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A107433 Slowest increasing sequence where some digit of a(n) and some digit of a(n+1) add up to 9. 2
0, 9, 10, 18, 19, 20, 27, 28, 31, 36, 37, 42, 45, 46, 50, 54, 55, 64, 65, 73, 76, 82, 87, 91, 98, 100, 108, 109, 110, 118, 119, 120, 127, 128, 129, 130, 136, 137, 138, 139, 140, 145, 146, 148, 149, 150, 154, 155, 158, 159, 160, 163, 164, 165, 168, 169, 170, 172, 173 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Starting with another "seed" than 0 would produce another sequence.

LINKS

Robert Israel, Table of n, a(n) for n = 0..10000

EXAMPLE

After 28 we must have an integer containing a "7" (2+"7"=9) or a "1" (8+"1"=9). The smallest integer satisfying this constraint is 31 (and not 37 or 41 or any other containing a "7" or a "1")

MAPLE

f:= proc(n) local S, k;

  S:= map(t -> 9-t, convert(convert(n, base, 10), set));

  for k from n+1 do

    if convert(convert(k, base, 10), set) intersect S <> {} then return k fi

  od

end proc:

a[0]:= 0:

for n from 1 to 100 do a[n]:= f(a[n-1]) od:

seq(a[n], n=0..100); # Robert Israel, Feb 24 2017

CROSSREFS

Sequence in context: A088036 A217935 A100595 * A090570 A131417 A268135

Adjacent sequences:  A107430 A107431 A107432 * A107434 A107435 A107436

KEYWORD

base,easy,nonn

AUTHOR

Eric Angelini, Jun 09 2005

EXTENSIONS

Corrected and extended by Zak Seidov, Jun 10 2005

STATUS

approved

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Last modified November 19 22:34 EST 2019. Contains 329323 sequences. (Running on oeis4.)