OFFSET
1,2
COMMENTS
EXAMPLE
a(3) = 90 because 90 has 3 divisors <= sqrt(90) of the form 4*j+1, namely 1, 5 and 9, and no smaller number works.
MAPLE
N:= 90: # for a(0) .. a(N)
f:= proc(n) nops(select(t -> t mod 4 = 1 and t^2 <= n, numtheory:-divisors(n))) end proc:
V:= Array(0..N): count:= 0:
for n from 1 while count < N+1 do
v:= f(n);
if v <= N and V[v] = 0 then V[v]:= n; count:= count+1 fi;
od:
convert(V, list);
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert Israel, Dec 29 2024
STATUS
approved