A268139 Semiprimes of the form 3*n*2^n - 3*n - 2^(2+n) + 4.
6, 35, 341, 2159, 6160337, 27787211, 191126044583, 412745898649251217229, 162789115166027506149234835193, 51436190754860636195130229261336259
Offset: 1
Keywords
Links
- Ben Green and Terence Tao, The primes contain arbitrarily long arithmetic progressions, Annals of Mathematics, 167 (2008), pp. 481-547. arXiv:math/0404188 [math.NT], 2004-2007.
Programs
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Magma
IsSemiprime:= func
; [s: n in [2..240] | IsSemiprime(s) where s is 3*n*2^n-3*n-2^(2+n)+4]; -
Mathematica
Select[Table[3 n 2^n - 3 n - 2^(2 + n) + 4, {n, 250}], PrimeOmega[#] == 2 &]