A103708 a(n+1) = d(n)+9 where d(n) is the n-th decimal digit in the concatenation of the digits in the sequence, starting with a(1)=1.

1, 10, 10, 9, 10, 9, 18, 10, 9, 18, 10, 17, 10, 9, 18, 10, 17, 10, 9, 10, 16, 10, 9, 18, 10, 17, 10, 9, 10, 16, 10, 9, 18, 10, 9, 10, 15, 10, 9, 18, 10, 17, 10, 9, 10, 16, 10, 9, 18, 10, 9, 10, 15, 10, 9, 18, 10, 17, 10, 9, 18, 10, 9, 10, 14, 10, 9, 18, 10, 17, 10, 9, 10, 16, 10, 9, 18, 10

Offset: 1

Author

Robert G. Wilson v, Feb 12 2005

Keywords

• base
• nonn

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A103700, A103701, A103702, A103703, A103704, A103705, A103706, A103707.

Programs

Maple

with(queue):
Q:= new(1): R:= 1:
for iter from 1 to 100 do
  v:= dequeue(Q)+9;
  R:= R, v;
  L:= convert(v,base,10);
  for i from 1 to nops(L) do enqueue(Q,L[-i]) od;
od:
R; # Robert Israel, Jul 06 2020

Mathematica

Flatten[ NestList[ Function[x, Flatten[ IntegerDigits[x] + 9]], {1}, 8]]

Extensions

Edited and corrected by Robert Israel, Jul 06 2020