OFFSET
1,2
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..10000
EXAMPLE
n=267, 267*267/(2*2+6*6+7*7)=801, n=267 belongs to the sequence.
MAPLE
filter:= proc(n)
type(n^2/convert(map(`^`, convert(n, base, 10), 2), `+`), integer)
end proc:
select(filter, [$1..1000]); # Robert Israel, Aug 03 2015
MATHEMATICA
Select[Range[600], Divisible[#^2, Plus @@ (IntegerDigits[#]^2)] &] (* Ivan Neretin, Aug 03 2015 *)
PROG
(PARI) k(n)=apply(sqr, digits(n));
is_ok(n)=my(kk=vecsum(k(n))); n*n\kk===n*n/kk;
first(m)=my(v=vector(m), k=1); for(i=1, m, while(!is_ok(k), k++); v[i]=k; k++); v; \\ Anders Hellström, Aug 03 2015
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Ctibor O. Zizka, Sep 07 2010
STATUS
approved