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A263400 Smallest index k such that Fibonacci(k) contains Fibonacci(n) as a proper substring in decimal notation. 1
15, 7, 7, 8, 7, 10, 11, 26, 26, 31, 40, 66, 79, 40, 132, 64, 58, 339, 433, 387, 254, 1158, 691, 74, 623, 1450, 3136, 3867, 1066, 1801, 953, 10392, 6051, 4677, 6092, 7445, 17382, 19526, 27332, 28226, 102495, 84345, 36245, 44281, 102373, 238850, 163880, 308518 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Chai Wah Wu, Table of n, a(n) for n = 0..54

EXAMPLE

a(7) = 26 because Fibonacci(26) = 121393 contains Fibonacci(7) = 13.

MAPLE

with(combinat, fibonacci):

printf("%d %d \n", 0, 15):

for n from 1 to 26 do:

ii:=0:fn:=fibonacci(n):l:=length(fn) :

  for k from 1 to 10000 while(ii=0) do:

   fk:=fibonacci(k):xk:=convert(fk, base, 10):nk:=nops(xk):

   n1:=nk-l+1:

    for j from 1 to n1 while(ii=0) do:

     s:=sum('xk[j+i-1]*10^(i-1)', 'i'=1..l):

      if s=fn and fn<>fk

      then

      ii:=1:printf("%d %d \n", n, k):

      else

      fi:

     od:

    od:

   od:

MATHEMATICA

Table[k = 1; While[Nand[StringContainsQ[ToString@ Fibonacci@ k, ToString@ Fibonacci@ n], Fibonacci@ k != Fibonacci@ n], k++]; k, {n, 0, 38}] (* Michael De Vlieger, Oct 19 2015 *)

PROG

(Python)

from gmpy2 import fib2, digits

def A263400(n):

    b, a = fib2(n)

    s, m = digits(b), n

    while True:

        a, b, m = b, a+b, m+1

        t = digits(b)

        if b > a and s in t:

            return m # Chai Wah Wu, Oct 27 2015

CROSSREFS

Cf. A263393.

Sequence in context: A040213 A097532 A033335 * A240909 A133817 A173447

Adjacent sequences:  A263397 A263398 A263399 * A263401 A263402 A263403

KEYWORD

nonn,base

AUTHOR

Michel Lagneau, Oct 17 2015

EXTENSIONS

a(31) - a(47) from Michael De Vlieger, Oct 19 2015

STATUS

approved

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Last modified July 11 22:52 EDT 2020. Contains 335652 sequences. (Running on oeis4.)