OFFSET
1,1
COMMENTS
If, as is conjectured, the last term of A018890 is 8042, there are no more terms than those shown. - Robert Israel, Jul 14 2014
EXAMPLE
a(1) = 7 = 1^3 + 1^3 + 1^3 + 1^3 + 1^3 + 1^3 + 1^3.
a(2) = 47 = 3^3 + 2^3 + 2^3 + 1^3 + 1^3 + 1^3 + 1^3.
a(3) = 61 = 3^3 + 2^3 + 2^3 + 2^3 + 2^3 + 1^3 + 1^3.
a(4) = 103 = 4^3 + 3^3 + 2^3 + 1^3 + 1^3 + 1^3 + 1^3.
MAPLE
for n from 1 to 10^4 do
m:= floor(n^(1/3));
if m^3 = n then M[n]:= 1
else
M[n]:= 1 + min(seq(M[n-j^3], j=1..m));
fi
od:
select(n -> M[n]=7 and isprime(n), [$1..10^4]); # Robert Israel, Jul 14 2014
CROSSREFS
KEYWORD
nonn,less,fini
AUTHOR
Rafael F. Farias, Jul 13 2014
STATUS
approved