OFFSET
1,1
EXAMPLE
20 is a member since 2^4 + 0^4 + 20 = 6^2,
47 is a member since 4^4 + 7^4 + 47 = 52^2,
104 is a member since 1^4 + 0^4 + 4^4 = 104 = 19^2,
113 is a member since 1^4 + 1^4 + 3^4 + 113 = 14^2.
MAPLE
filter:= proc(n) local L, k;
issqr(n + add(t^4, t=convert(n, base, 10)))
end proc:
select(filter, [$1..20000]); # Robert Israel, Jan 30 2021
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Will Gosnell, Jan 30 2021
STATUS
approved