Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 Jan 23 2022 07:30:47
%S 0,1,2,3,4,5,6,7,8,9,19,15,25,16,26,17,27,18,59,78,69,88,79,98,89,108,
%T 99,509,618,609,718,709,818,809,918,909,5009,6018,6009,7018,7009,8018,
%U 8009,9018,9009,50009,60018,60009,70018,70009,80018,80009,90018
%N Smallest m such that A259043(m) = n.
%C A259043(a(n)) = n and A259043(m) != n for m < a(n).
%H Reinhard Zumkeller, <a href="/A259046/b259046.txt">Table of n, a(n) for n = 0..76</a>
%o (Haskell)
%o import Data.List (elemIndex); import Data.Maybe (fromJust)
%o a259046 = fromJust . (`elemIndex` (map a259043 [0..]))
%o (PARI) f(n) = if (n<10, n, my(u=n%10); f(n\10 + u) + u); \\ A259043
%o a(n) = my(m=0); while (f(m)!=n, m++); m; \\ _Michel Marcus_, Jan 23 2022
%Y Cf. A259043, A051885.
%K nonn
%O 0,3
%A _Reinhard Zumkeller_, Jun 17 2015