A105708 - OEIS

%I #9 Feb 16 2025 08:32:57

%S 6,11,28,23,38,30,49,50,46,60,54,83,71,81,73,78,90,90,99,97,126,114,

%T 113,135,121,146,136,145,140,145,154,157,170,164,178,186,180,190,188,

%U 203,200,211,207,215,221,246,235,231,242,249,247,272,255,269,267,290,274

%N Smallest m such that 8 is at the n-th position of the decimal representation of the m-th Fibonacci number.

%C A105718(n) = A000045(a(n)).

%H Robert Israel, <a href="/A105708/b105708.txt">Table of n, a(n) for n = 0..5000</a>

%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/FibonacciNumber.html">Fibonacci Number</a>

%e n=3: a(3)=23, A000045(23)=A105718(3)=28657->2[8]657;

%e n=4: a(4)=38, A000045(38)=A105718(4)=39088169->390[8]8169.

%p N:= 100: # for a(0)..a(N)

%p V:= Array(0..N): count:= 0:

%p for m from 1 while count < N+1 do

%p   v:= combinat:-fibonacci(m);

%p   L:= convert(v,base,10);

%p   S:= map(t -> t-1, select(t -> L[t]=8, [$1..nops(L)]));

%p   for s in S do if s <= N and V[s] = 0 then count:= count+1; V[s]:= m fi

%p od od:

%p convert(V,list); # _Robert Israel_, Apr 25 2021

%Y Cf. A105701, A072354, A105702, A105703, A105704, A105705, A105706, A105707, A105709.

%K nonn,base

%O 0,1

%A _Reinhard Zumkeller_, Apr 18 2005