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A105707
Smallest m such that 7 is at the n-th position of the decimal representation of the m-th Fibonacci number.
11
14, 14, 20, 22, 25, 34, 42, 47, 44, 49, 66, 66, 65, 68, 96, 81, 87, 89, 92, 101, 116, 145, 111, 116, 129, 153, 132, 135, 167, 159, 159, 156, 159, 168, 175, 176, 178, 183, 217, 198, 199, 202, 221, 223, 249, 223, 226, 235, 266, 243, 245, 250, 258, 265, 266, 269
OFFSET
0,1
COMMENTS
Positions start with the 0th position on the right. - Robert Israel, Jun 01 2020
LINKS
Eric Weisstein's World of Mathematics, Fibonacci Number
FORMULA
A000045(a(n)) = A105717(n).
EXAMPLE
n=3: a(3)=22, A000045(22) = A105710(3) = 17711 -> 1[7]711;
n=4: a(4)=25, A000045(25) = A105710(4) = 75025 -> [7]5025.
MAPLE
N:= 100: # for a(0) to a(N)
F[0]:= 0: F[1]:= 1:
V:= Array(0..N):
count:= 0:
for m from 2 while count < N+1 do
F[m]:= F[m-1]+F[m-2];
L:= convert(F[m], base, 10);
M:= select(t -> L[t+1]=7 and V[t]=0, [$0..min(N, nops(L)-1)]);
count:= count + nops(M);
V[M]:= m;
od:
convert(V, list); # Robert Israel, Jun 01 2020
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Apr 18 2005
STATUS
approved