A217165 a(n) is the least value of k such that the decimal expansion of Fibonacci(k) contains n consecutive identical digits.

0, 10, 49, 66, 118, 883, 2202, 6493, 62334, 135241, 353587, 1162507, 5155873, 7280413, 37356153

Offset

1,2

Comments

a(16) > 42000000. - Paul Geneau de Lamarlière, Feb 04 2024

a(16) > 10^8. - Nick Hobson, Feb 09 2024

Links

Table of n, a(n) for n=1..15.

Nick Hobson, C program

Mathematica

k = 0; Join[{0}, Table[While[d = IntegerDigits[Fibonacci[k]]; ! MemberQ[Partition[Differences[d], n - 1, 1], Table[0, {n - 1}]], k++]; k, {n, 2, 8}]] (* T. D. Noe, Oct 02 2012 *)

Prog

(Python)
def A217165(n):
....if n == 1:
........return 0
....else:
........l, y, x = [str(d)*n for d in range(10)], 0, 1
........for m in range(1, 10**9):
............s = str(x)
............for k in l:
................if k in s:
....................return m
............y, x = x, y+x
........return 'search limit reached'
# Chai Wah Wu, Dec 17 2014
(C) See Links section.

Crossrefs

Cf. A000045, A045875, A215727, A215728, A215729, A215730, A215731.

Sequence in context: A264266 A048698 A045770 * A154066 A056578 A370216

Adjacent sequences: A217162 A217163 A217164 * A217166 A217167 A217168

Keyword

nonn,base,hard

Author

V. Raman, Sep 27 2012

Extensions

a(10)-a(11) from Chai Wah Wu, Dec 17 2014

a(12)-a(15) from Paul Geneau de Lamarlière, Feb 04 2024

Status

approved