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A088099
Group the natural numbers with at least two members in each group such that the n-th group sum is a multiple of n: (1, 2), (3, 4, 5), (6, 7, 8), (9, 10, 11, 12, 13, 14, 15), (16, 17, 18, 19), (20, 21, 22, 23, 24, 25, 26, 27, 28), (29, 30, 31, 32, 33, 34), ... Sequence contains the group sums.
2
3, 12, 21, 84, 70, 216, 189, 440, 396, 280, 242, 192, 858, 1092, 465, 3568, 2312, 1188, 2907, 3420, 1155, 990, 2691, 1080, 2925, 1170, 3159, 1260, 3393, 1350, 3627, 1440, 3861, 1530, 4095, 1620, 4329, 1710, 4563, 1800, 4797, 1890, 5031, 1980, 5265, 2070
OFFSET
1,1
COMMENTS
The condition 'at least two terms' is imposed to avoid the trivial grouping (1),(2),(3),(4),(5),... a(n) == 0 (mod n) by definition.
CROSSREFS
Sequence in context: A061262 A051656 A074004 * A375986 A110419 A031223
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Sep 24 2003
EXTENSIONS
More terms from Ray Chandler, Sep 26 2003
STATUS
approved