OFFSET
1,3
COMMENTS
The subsequence of primes begins: 2, 3, 5, 11, 17, 23, 41, 53, 67, 71, 101, 107, 113, 131, 139, 157, 193, 229, 233, 251 ... - Dario Piazzalunga, Jan 03 2013
The subsequence of Fibonacci numbers begins: 0, 1, 2, 3, 5, 8, 21, 233, ... (no more up to 100000). - Dario Piazzalunga, Jan 03 2013
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000
MAPLE
isA000045 := proc(n)
local i, f;
for i from 0 do
f := combinat[fibonacci](i) ;
if f = n then
return true;
elif f > n then
return false;
end if;
end do:
end proc:
isA028840 := proc(n)
isA000045(A007953(n)) ;
end proc:
for n from 0 to 1000 do
if isA028840(n) then
printf("%d, ", n);
end if;
end do: # R. J. Mathar, Apr 17 2013
# second Maple program:
q:= proc(n) option remember; (t->
issqr(t+4) or issqr(t-4))(5*n^2)
end:
a:= proc(n) option remember; local k; for k from
`if`(n=1, 0, 1+a(n-1)) while not q(
add(i, i=convert(k, base, 10))) do od; k
end:
seq(a(n), n=1..66); # Alois P. Heinz, Jan 28 2020
MATHEMATICA
f = Union[Fibonacci[Range[0, 8]]]; t = {}; n = 0; While[c = Total[IntegerDigits[n]]; c < f[[-1]], If[MemberQ[f, c], AppendTo[t, n]]; n++]; t (* T. D. Noe, Jan 03 2013 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
EXTENSIONS
More terms from Erich Friedman
0 inserted by Dario Piazzalunga, Jan 03 2013
STATUS
approved