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A072352
a(n) is the largest n-digit Fibonacci number.
3
8, 89, 987, 6765, 75025, 832040, 9227465, 63245986, 701408733, 7778742049, 86267571272, 956722026041, 6557470319842, 72723460248141, 806515533049393, 8944394323791464, 99194853094755497, 679891637638612258, 7540113804746346429, 83621143489848422977
OFFSET
1,1
LINKS
FORMULA
a(n) = A000045(A072353(n)). - Robert Israel, Mar 10 2016
EXAMPLE
a(3)=987, as 987 is largest 3-digit Fibonacci number.
MAPLE
fib:= combinat:-fibonacci:
g:= proc(x) local n;
n:= floor(ln((2*x+1)*sqrt(5)/2)/ln((1+sqrt(5))/2));
if fib(n) > x then while fib(n) > x do n:= n-1 od
elif fib(n+1) <= x then while fib(n+1) <= x do n:= n+1 od
fi;
fib(n)
end:
seq(g(10^n), n=1..50); # Robert Israel, Mar 10 2016
# second Maple program:
F:= proc(n) option remember; local f;
f:= `if`(n=1, [1$2], F(n-1));
do f:= [f[2], f[1]+f[2]];
if length(f[1])<length(f[2]) then break fi
od; f
end:
a:= n-> F(n)[1]:
seq(a(n), n=1..25); # Alois P. Heinz, Mar 10 2016
MATHEMATICA
Table[k=1; While[Fibonacci@++k<10^n]; Fibonacci[k-1], {n, 20}] (* Giorgos Kalogeropoulos, Jul 06 2021 *)
PROG
(Python)
def A072352_list(n):
list = []
x, y = 1, 1
while len(list) < n:
if len(str(x)) < len(str(y)):
list.append(x)
x, y = y, x + y
return list
print(A072352_list(20)) # M. Eren Kesim, Jun 28 2021
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Shyam Sunder Gupta, Jul 17 2002
STATUS
approved