OFFSET
1,1
EXAMPLE
a(4) = 2*3*3*3+1 = 55.
MAPLE
f:= proc(n) local pq, t, v, i, q;
uses priqueue;
initialize(pq);
insert([-2^n, 2$n], pq);
do
t:= extract(pq);
v:= -t[1];
if issqr(9+8*v) then return v+1 fi;
q:= nextprime(t[-1]);
for i from 1 to n while t[-i] = t[-1] do
insert([t[1]*(q/t[-1])^i, op(t[2..-i-1]), q$i], pq)
od;
od
end proc:
map(f, [$1..30]); # Robert Israel, Aug 13 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Apr 02 2003
EXTENSIONS
Extended and edited by Ryan Propper, Jun 21 2005
a(24)-a(26) from Donovan Johnson, Jan 31 2009
a(27)-a(30) from Robert Israel, Aug 13 2024
STATUS
approved