A283598 Numbers n such that all three of 6*n+1, 6*(n+1)+1, and 6*(n+2)+1 are semiprimes.

41, 42, 48, 84, 92, 148, 157, 158, 162, 189, 209, 210, 222, 223, 224, 225, 226, 234, 250, 306, 315, 316, 317, 318, 319, 326, 386, 387, 401, 407, 408, 433, 462, 487, 488, 489, 514, 515, 521, 532, 539, 566, 567, 568, 569, 580, 598, 633, 634, 662, 663, 664, 672, 697, 713, 717, 718

Offset

1,1

Comments

That is, n, n+1 and n+2 are terms in A112775.

Links

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

Mathematica

po[x_]=PrimeOmega[x]; Select[Range[1000], po[6*#+1]==po[6*(1+#)+1]== po[6*(2+#)+1==2 &]
Select[Range[800], PrimeOmega[6#+{1, 7, 13}]=={2, 2, 2}&] (* Harvey P. Dale, Apr 23 2024 *)

Crossrefs

Subsequence of A283597 and A112775.

Cf. A112771, A001358.

Sequence in context: A165862 A339568 A077680 * A041839 A098064 A073921

Adjacent sequences: A283595 A283596 A283597 * A283599 A283600 A283601

Keyword

nonn

Author

Zak Seidov, Mar 14 2017

Status

approved