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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.
4
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
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
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