%I
%S 4,34,274,2276,8126,184876,446876,18671876,95234374,1144976876,
%T 6018359374,281025390626,2068291015624,6254345703124
%N a(n) is the smallest even number k such that k1 and k+1 are both nalmost primes.
%C 10^13 < a(15) <= 181171630859374.  _Giovanni Resta_, Jun 21 2020
%H David A. Corneth, <a href="/A335667/a335667.gp.txt">Upper bounds on a(n) for n = 1..37 where values with * are proven values</a>
%e a(1) = 4 since 4  1 and 4 + 1 are both primes.
%e a(2) = 34 since 34  1 = 33 = 3*11 and 34 + 1 = 35 = 5*7 are both semiprimes.
%e a(3) = 274 since 274  1 = 273 = 3*7*13 and 274 + 1 = 275 = 5^2 * 11 are both 3almost primes.
%t m = 8; v = Table[0, {m}]; c = 0; o1 = 1; n = 4; While[c < m, o2 = PrimeOmega[n + 1]; If[o1 == o2 && v[[o1]] == 0, c++; v[[o1]] = n]; o1 = o2; n += 2]; v
%Y Cf. A001222, A088077, A115186, A154704.
%K nonn,more
%O 1,1
%A _Zak Seidov_ and _Amiram Eldar_, Jun 17 2020
%E a(12)a(14) from _Giovanni Resta_, Jun 21 2020
