OFFSET
0,3
MAPLE
isA002378 := proc(n)
if issqr(1+4*n) then
(sqrt(1+4*n)-1) /2 ;
type(%, 'integer') ;
else
false;
end if;
end proc:
A214963 := proc(n)
option remember;
local k ;
if n <= 1 then
1;
else
for k from procname(n-1)+1 do
if isA002378(k*procname(n-2)) then
return k;
end if;
end do:
end if;
end proc: # R. J. Mathar, Aug 10 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Aug 03 2012
STATUS
approved