A074131 Group successively larger prime numbers so that the sum of the n-th group is a multiple of n. Sequence gives the group sum divided by n for the n-th group.

2, 4, 6, 18, 12, 13, 79, 167, 527, 437, 66, 127, 1079, 170, 422, 1550, 542, 327, 1002, 112, 1215, 236, 2006, 394, 1685, 417, 2097, 3681, 5892, 2838, 1779, 2775, 214, 1262, 5696, 679, 2377, 7926, 28463, 9505, 20618, 6653, 6754, 1585, 13266, 6173, 5587

Offset

1,1

Links

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

Formula

A074128(n)/n.

Mathematica

NextPrime[ n_ ] := Block[ {k = n + 1}, While[ ! PrimeQ[ k ], k++ ]; k ]; a = {}; k = 1; Do[ s = 0; While[ k = NextPrime[ k ]; s = s + k; !IntegerQ[ s/n ], ]; a = Append[ a, s/n ], {n, 1, 50} ]; a

Crossrefs

Cf. A000040, A074128, A074129, A074130.

Sequence in context: A192335 A334390 A067993 * A355078 A335038 A019464

Adjacent sequences: A074128 A074129 A074130 * A074132 A074133 A074134

Keyword

nonn

Author

Amarnath Murthy, Aug 27 2002

Extensions

(2), (3, 5), (7, 11), (13, 17, 19, 23), (29, 31), (37, 41), (43, 47, 53, 59, 61, 67, 71, 73, 79), (83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139), (149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, ..., 269), ...

Edited, corrected and extended by Robert G. Wilson v, Aug 29 2002

Status

approved