A074129 Group successively larger prime numbers so that the sum of the n-th group is a multiple of n. Sequence gives the first term of each group.

2, 3, 7, 13, 29, 37, 43, 83, 149, 271, 359, 373, 397, 587, 607, 661, 883, 967, 1009, 1117, 1129, 1291, 1307, 1559, 1601, 1787, 1847, 2069, 2411, 2917, 3181, 3319, 3529, 3539, 3623, 4051, 4099, 4271, 4871, 6553, 7019, 8081, 8377, 8693, 8747, 9343, 9619

Offset

1,1

Links

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

Mathematica

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

Crossrefs

Cf. A000040, A074128, A074130, A074131.

Sequence in context: A048573 A221834 A006946 * A233042 A055003 A175248

Adjacent sequences: A074126 A074127 A074128 * A074130 A074131 A074132

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