A328036 Even semiprimes such that the next semiprime is also even.

4, 10, 58, 274, 382, 454, 458, 538, 614, 1082, 1234, 1318, 1478, 1618, 1718, 1874, 2062, 2374, 2554, 2846, 2902, 3574, 3722, 3998, 4174, 4258, 4474, 4946, 5098, 5414, 5422, 5498, 6334, 6598, 6658, 6686, 6718, 6778, 6914, 6922, 7054, 7346, 7534, 7642, 7702, 7754, 7838, 8038, 8098, 8422, 8434, 8674, 8818

Offset: 1

Author

J. M. Bergot and Robert Israel, Oct 02 2019

Keywords

• nonn

Examples

			a(3)=58 is a member because 58=2*29 is an even semiprime and the next semiprime is 62, which is also even.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001358. Includes 2*A069142.

Programs

Maple

sp:= select(t -> numtheory:-bigomega(t)=2, [$1..20000]):
sp[select(t -> sp[t]::even and sp[t+1]::even, [$1..nops(sp)-1])];

Mathematica

Select[Partition[Select[Range[10000],PrimeOmega[#]==2&],2,1],AllTrue[#,EvenQ]&][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 01 2020 *)