%I #35 Oct 05 2023 14:27:50
%S 2,5,13,83,463,4217,169333,2273237,23239523,512974197,5572561567
%N a(n) is the smallest positive number k such that k^2 - 1 and k^2 + 1 each have exactly n distinct prime divisors.
%F a(n) >= max(A219017(n), A180278(n)). - _Daniel Suteu_, Sep 03 2023
%o (PARI) isok(k, n) = (omega(k^2-1)==n) && (omega(k^2+1)==n);
%o a(n) = my(k=2); while (!isok(k, n), k++); k; \\ _Michel Marcus_, Sep 03 2023
%Y Cf. A001221, A180278, A219017.
%Y Cf. A088075 (with k instead of k^2).
%K nonn,more
%O 1,1
%A _Juri-Stepan Gerasimov_, Sep 01 2023
%E a(9)-a(11) from _Amiram Eldar_, Sep 03 2023