A337016 a(0) = 0. Successive terms are double the previous, then with their digits incremented by 1.

0, 1, 3, 7, 25, 61, 233, 577, 2265, 5641, 22393, 55897, 2228105, 5567321, 22245753, 555102617, 2221316345, 55537437101, 222185985313, 5554821081737, 222110753274585, 5553326176510281, 22217763464131673, 555466371039374457, 222110438531898591025

Offset

0,3

Comments

If 9 appears anywhere in the decimal expansion of 2*a(n-1), we replace that digit with 10 upon incrementing by 1. See a(12) of the Examples section and A216556 for more information.

Links

Table of n, a(n) for n=0..24.

Formula

a(n) = A216556(2*a(n-1)), a(0) = 0.

Example

To calculate a(12), double 55897 to get 111794, then increment the digits by 1 to get 2228105.
To calculate a(13), double 2228105 to get 4456210, then increment the digits by 1 to get 5567321.

Maple

a:= proc(n) option remember; `if`(n=0, 0, (l-> parse(cat(seq(
      l[-i]+1, i=1..nops(l)))))(convert(2*a(n-1), base, 10)))
    end:
seq(a(n), n=0..25);  # Alois P. Heinz, Dec 12 2020

Mathematica

NestList[FromDigits[Flatten@ Map[IntegerDigits, IntegerDigits[2 #] + 1]] &, 0, 24] (* Michael De Vlieger, Dec 11 2020 *)

Prog

(PARI) digs(n) = if (n==0, [0], digits(n));
lista(nn) = {a = 0; print1(a, ", "); for (n=1, nn, a = eval(concat(apply(t->Str(t+1), digs(2*a)))); print1(a, ", "); ); } \\ Michel Marcus, Nov 28 2020

Crossrefs

Cf. A000079, A061511, A089718.

Sequence in context: A161637 A329969 A287880 * A148721 A148722 A148723

Adjacent sequences: A337013 A337014 A337015 * A337017 A337018 A337019

Keyword

base,nonn

Author

Jamie Robert Creasey, Nov 21 2020

Status

approved