A030406 a(n)=least k such that base 4 representation of n begins at s(k), where s=A030401.

1, 7, 2, 15, 3, 8, 1, 39, 7, 51, 9, 63, 2, 6, 10, 87, 15, 103, 18, 17, 3, 29, 4, 41, 27, 53, 8, 65, 1, 5, 12, 215, 39, 231, 42, 247, 28, 7, 48, 279, 51, 295, 54, 311, 31, 55, 9, 343, 63, 359, 66, 14, 2, 26, 11, 38, 6, 50, 56, 62, 10, 37, 61, 471

Offset

1,2

Links

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

Formula

a(n) = min(a(4*n),a(4*n+1),a(4*n+2),a(4*n+3)). - Robert Israel, Jun 27 2018

Maple

B:= cat("", op(map(op, [seq(ListTools[Reverse](convert(2*n-1, base, 4)), n=1..500)]))):
g:= proc(n) local L, ns;
  L:= convert(n, base, 4);
  ns:= cat("", seq(L[-i], i=1..nops(L)));
  StringTools:-Search(ns, B);
end proc:
A:= NULL:
for n from 1 do
v:= g(n);
if v = 0 then break fi;
A:= A, v;
od:
A; # Robert Israel, Jun 27 2018

Crossrefs

Cf. A030401.

Sequence in context: A070429 A050092 A293452 * A336194 A332209 A239975

Adjacent sequences: A030403 A030404 A030405 * A030407 A030408 A030409

Keyword

nonn,look

Author

Clark Kimberling

Status

approved