A101434 Composite numbers which are the product of non-twin primes.

4, 8, 16, 32, 46, 64, 74, 92, 94, 106, 128, 134, 148, 158, 166, 178, 184, 188, 194, 212, 226, 254, 256, 262, 268, 296, 314, 316, 326, 332, 334, 346, 356, 368, 376, 388, 422, 424, 446, 452, 466, 502, 508, 512, 514, 524, 526, 529, 536, 554, 586, 592, 614, 628, 632

Offset

1,1

Links

Table of n, a(n) for n=1..55.

Example

74 = 2*37, 529 = 23*23.

Mathematica

nn = 150; p = Prime[Range[nn]]; t = {2}; Do[If[p[[n + 1]] - p[[n]] != 2 && p[[n]] - p[[n - 1]] != 2, AppendTo[t, p[[n]]]], {n, 2, nn - 1}]; Select[Range[2, t[[-1]]], ! PrimeQ[#] && Complement[Transpose[FactorInteger[#]][[1]], t] == {} &] (* T. D. Noe, May 21 2013 *)

Crossrefs

Cf. A100819.

Sequence in context: A088259 A123857 A217313 * A293780 A048168 A175341

Adjacent sequences: A101431 A101432 A101433 * A101435 A101436 A101437

Keyword

easy,nonn

Author

Walter Carlini, Jan 18 2005

Extensions

Corrected and extended by Arkadiusz Wesolowski, May 21 2013

Status

approved