A062525 8^a(n) is smallest power of 8 containing the string 'n'.

4, 0, 3, 5, 2, 3, 2, 5, 1, 4, 10, 14, 3, 9, 6, 7, 8, 9, 10, 12, 7, 6, 17, 21, 10, 17, 6, 5, 9, 20, 26, 25, 5, 21, 9, 15, 12, 10, 13, 14, 4, 10, 9, 14, 6, 11, 14, 12, 17, 13, 18, 3, 7, 29, 13, 13, 16, 25, 11, 11, 20, 25, 6, 27, 2, 14, 24, 8, 5, 20, 23, 7, 8, 10, 10, 13

Offset

0,1

Links

Robert Israel, Table of n, a(n) for n = 0..9999

Maple

F:= proc(dmax) local R, count, x, N, L, d, i, v, p;
count:= 0: x:= 1/8: N:= 10^dmax:
for p from 0 while count < N do
  x:= 8*x;
  L:= convert(x, base, 10);
  for d from 1 to min(dmax, nops(L)) do
    for i from 1 to nops(L)-d+1 do
      v:= add(L[j]*10^(j-i), j=i..i+d-1);
      if not assigned(R[v]) then count:= count+1; R[v]:= p fi
od od od;
seq(R[v], v=0..N-1);
end proc:
F(2); # Robert Israel, Dec 25 2019

Mathematica

Table[k = 0; While[ StringPosition[ ToString[8^k], ToString[n] ] == {}, k++ ]; k, {n, 0, 75} ]
Join[{4, 0}, With[{c=Table[{n, IntegerDigits[8^n]}, {n, 50}]}, Table[ SelectFirst[ c, SequenceCount[ #[[2]], IntegerDigits[k]]>0&], {k, 2, 80}]][[All, 1]]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 13 2019 *)

Crossrefs

Cf. A030000, A063571, A176768.

Sequence in context: A092512 A060568 A073466 * A085655 A338656 A153615

Adjacent sequences: A062522 A062523 A062524 * A062526 A062527 A062528

Keyword

base,nonn

Author

Robert G. Wilson v, Jun 24 2001

Status

approved