A182477 Primes of the form p*q*r + 2, where p, q and r are distinct primes.

107, 167, 197, 233, 257, 347, 359, 401, 431, 457, 467, 557, 563, 617, 647, 653, 743, 761, 797, 863, 887, 937, 971, 1087, 1097, 1187, 1223, 1237, 1283, 1297, 1409, 1481, 1493, 1549, 1553, 1583, 1597, 1601, 1607, 1637, 1697, 1871, 1889, 1907, 1949, 2003, 2017

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Formula

{A007304(n)+2} INTERSECTION {A000040}.

Example

107 = 3*5*7+2.

Mathematica

mx = 50; ps = Prime[Range[2, mx + 1]]; t = Table[ps[[i]]*ps[[j]]*ps[[k]] + 2, {i, mx}, {j, i + 1, mx}, {k, j + 1, mx}]; Select[Union[Flatten[t]], # <= 3*5*ps[[-1]] + 2 && PrimeQ[#] &] (* T. D. Noe, May 01 2012 *)

Crossrefs

Cf. A115267.

Sequence in context: A168475 A142662 A178416 * A229570 A107215 A142142

Adjacent sequences: A182474 A182475 A182476 * A182478 A182479 A182480

Keyword

nonn

Author

Alex Ratushnyak, May 01 2012

Status

approved