A217192 a(n) is the number of digits in the decimal representation of the smallest Lucas number that contains n consecutive identical digits.
1, 2, 8, 17, 24, 113, 657, 1346, 3667, 17318, 68642, 355612, 355612, 1678243, 1678243, 16207565
Offset: 1
Programs
-
Mathematica
k = 0; Join[{1}, Table[While[d = IntegerDigits[LucasL[k]]; ! MemberQ[Partition[Differences[d], n - 1, 1], Table[0, {n - 1}]], k++]; Length[d], {n, 2, 8}]] (* T. D. Noe, Oct 02 2012 *) -
Python
def A217192(n): if n == 1: return 1 else: l, y, x = [str(d)*n for d in range(10)], 2, 1 for m in range(1, 10**9): s = str(x) for k in l: if k in s: return len(s) y, x = x, y+x return 'search limit reached' # Chai Wah Wu, Dec 17 2014
Extensions
a(11) from Chai Wah Wu, Dec 17 2014
a(12)-a(16) from Nick Hobson, Feb 04 2024
Comments