OFFSET
0,2
MAPLE
p:= proc(n) option remember; `if`(n=0, 1,
p(n-1)*(x^ithprime(n)+1/x^ithprime(n))^2)
end:
a:= n-> coeff(p(n), x, 0):
seq(a(n), n=0..30); # Alois P. Heinz, Jan 26 2022
MATHEMATICA
p[n_] := p[n] = If[n == 0, 1, p[n - 1]*(x^Prime[n] + 1/x^Prime[n])^2];
a[n_] := Coefficient[p[n], x, 0];
Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Mar 01 2022, after Alois P. Heinz *)
PROG
(PARI) a(n) = polcoef (prod(k=1, n, (x^prime(k) + 1/x^prime(k))^2), 0); \\ Michel Marcus, Jan 21 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 20 2022
STATUS
approved