A176507 Indices of products of 2 single (or isolated or non-twin) primes in the composites.

1, 31, 52, 69, 78, 101, 120, 127, 137, 149, 177, 199, 206, 248, 259, 266, 277, 339, 359, 375, 406, 416, 426, 429, 452, 479, 501, 518, 540, 551, 579, 590, 603, 613, 623, 630, 640, 655, 662, 676, 704, 726, 732, 743, 757, 775, 795, 809, 816, 829, 837, 847, 900

Offset: 1

Author

Juri-Stepan Gerasimov, Apr 19 2010

Keywords

• nonn

Formula

A002808(k)=A176312(a(n)).

Extensions

Corrected (553 replaced by 551) by R. J. Mathar, May 02 2010