A366167 Semiprimes that are the sum of two successive terms of A092192.

25, 146, 201, 221, 249, 302, 365, 529, 662, 681, 849, 949, 1211, 1282, 1318, 1343, 1849, 2517, 3223, 3398, 3466, 3635, 3867, 3949, 4063, 4749, 4819, 4997, 5158, 6049, 6614, 7023, 7041, 7066, 7117, 7921, 8314, 8471, 8709, 8727, 8914, 8981, 9155, 9235, 9299, 9563, 10741, 10895, 10958, 11435, 11962

Offset: 1

Author

Zak Seidov and Robert Israel, Oct 02 2023

Keywords

• nonn

Examples

			a(3) = 201 is a term because 201 = 95 + 106 = A092192(7) + A092192(8).
		

Links

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

Crossrefs

Cf. A001358, A092192.

Programs

Maple

SP:= select(t -> numtheory:-bigomega(t) = 2, [$1..10000]):
A092192:= select(t -> numtheory:-bigomega(t) = 2, SP[2..-1]+SP[1..-2]):
select(t -> numtheory:-bigomega(t) = 2, A092192[2..-1]+A092192[1..-2]);

Mathematica

sim = Select[Range[4, 100000], 2 == PrimeOmega[#];&]; se = Select[Drop[sim, 1]
+ Drop[sim, -1], 2 == PrimeOmega[#] &];    Select[Drop[se, 1] + Drop[se, -1], 2
== PrimeOmega[#] &]

PARI

upto(n) = {my(pr = 10, res = List(), semiprimes = List([4,6])); forfactored(i = 9, n, if(bigomega(i[2]) == 2, listpop(semiprimes, 1); listput(semiprimes, i[1]); s = semiprimes[1] + semiprimes[2]; if(bigomega(s) == 2, c = s + pr; if(c > n, return(res)); if(bigomega(c) == 2, listput(res, c)); pr = s))); res} \\ David A. Corneth, Oct 02 2023