A146560 Squarefree semiprimes n such that n+1 is squarefree and n+2 is prime

21, 57, 65, 69, 77, 129, 177, 209, 221, 237, 309, 329, 365, 381, 417, 437, 497, 501, 545, 597, 681, 689, 717, 785, 905, 965, 1037, 1101, 1121, 1257, 1317, 1397, 1437, 1497, 1509, 1541, 1569, 1577, 1661, 1757, 1821, 1829, 1865, 1929, 1977, 1985, 2201, 2369, 2577, 2589, 2669, 2705, 2885, 2901

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Formula

(A006881 INTERSECT A040976) INTERSECT A005117

Mathematica

Select[Range[3000], PrimeOmega[#]==2&&SquareFreeQ[#]&&SquareFreeQ[#+1]&&PrimeQ[#+2]&] (* Harvey P. Dale, Jan 20 2020 *)

Crossrefs

Cf. A077064, A146319.

Sequence in context: A183310 A280884 A257103 * A174969 A176069 A043382

Adjacent sequences: A146557 A146558 A146559 * A146561 A146562 A146563

Keyword

easy,nonn

Author

Giovanni Teofilatto, Nov 01 2008

Extensions

Definition corrected and more terms supplied by R. J. Mathar, Nov 02 2008

Status

approved