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%I #18 Aug 22 2015 20:06:10
%S 1,2,4,5,10,8,14,7,26,13,20,16,17,34,32,12,6,3,24,30,15,18,9,72,27,54,
%T 45,36,63,126,28,35,42,21,56,43,86,136,51,48,40,50,25,74,37,62,31,68,
%U 64,80,19,38,61,122,76,23,46,53,106,92,115,218,109,224,84
%N Smallest integer not yet present such that [a(n)+a(n+1)] divides the concatenation [a(n),a(n+1)].
%D Posting by Eric Angelini to Sequence Fans Mailing List, Sep 21 2010
%H Alois P. Heinz, <a href="/A173660/b173660.txt">Table of n, a(n) for n = 1..10000</a>
%e 1+2 divides 12 -> 12/3=4
%e 2+4 divides 24 -> 24/6=4
%e 4+5 divides 45 -> 45/9=5
%e 5+10 divides 510 -> 510/15=34
%e 10+8 divides 108 -> 108/18=6
%e 8+14 divides 814 -> 814/22=37
%e ...
%p ina:= proc() false end:
%p ina(1):= true: mina:= 2;
%p a:= proc(n) option remember; global mina; local k;
%p if n=1 then 1
%p else for k from mina while ina(k) or
%p irem(parse(cat(a(n-1), k)), a(n-1)+k)<>0 do od;
%p ina(k):= true; while ina(mina) do mina:= mina+1 od;
%p k
%p fi
%p end:
%p seq(a(n), n=1..70); # _Alois P. Heinz_, Sep 30 2011
%K nonn,base
%O 1,2
%A _N. J. A. Sloane_, Nov 24 2010
%E Corrected and extended by _Alois P. Heinz_, Sep 30 2011
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