A092945 Group the natural numbers so that the n-th group contains n numbers whose sum as well as the group product + 1 is prime. Sequence contains the last term of each group.

2, 4, 10, 9, 23, 28, 29, 47, 115, 71, 88, 214, 215, 188, 341, 133, 220, 372, 250, 321, 227, 311, 281, 310, 592, 857, 691, 406, 470, 483, 904, 903, 707, 601, 876, 727, 726, 1299, 828, 925, 1217, 1254, 963, 1426, 1213, 1394, 2108, 1356, 1448, 1286, 1564, 1455

Offset

1,1

Comments

Sequence is underdefined. The original author may have intended to say that the terms must be distinct and minimal; perhaps he should clarify. - Jonathan Vos Post, Mar 22 2006

See A092944 for additional clarification of definition.

Links

Table of n, a(n) for n=1..52.

Example

a(6) = 28 because 15+16+17+18+19+28 = 113 is prime and 15*16*17*18*19*28 + 1 = 39070081 is prime.

Crossrefs

Cf. A092944, A092946, A092947.

Sequence in context: A173824 A356603 A097211 * A320150 A056376 A185372

Adjacent sequences: A092942 A092943 A092944 * A092946 A092947 A092948

Keyword

nonn

Author

Amarnath Murthy, Mar 23 2004

Extensions

a(6) from Jonathan Vos Post, Mar 22 2006

Edited and extended by Ray Chandler, May 07 2008

Status

approved