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A093839
Lexicographically earliest sequence of distinct positive integers such that the n-th partial sum and n-th partial product are divisible by n.
4
2, 4, 3, 11, 5, 17, 7, 15, 8, 18, 9, 57, 13, 27, 14, 30, 32, 16, 35, 37, 39, 107, 23, 47, 24, 50, 25, 137, 29, 89, 31, 63, 65, 33, 68, 34, 71, 73, 36, 236, 41, 125, 43, 87, 44, 90, 45, 93, 46, 96, 98, 308, 53, 161, 55, 111, 56, 114, 116, 238, 61, 123, 62, 126, 128, 262, 67
OFFSET
1,1
EXAMPLE
1 is divisible by 1, but a(1) cannot be 1, because a(2) would have to be odd to make an even sum, but even to make an even product. Similarly, 2+4+3+7 and 2*4*3*7 are both divisible by 4, but if a(4) were 7 then a(5) would not exist, so a(4) = 11.
CROSSREFS
KEYWORD
nonn,easy,less
AUTHOR
Amarnath Murthy, Apr 18 2004
EXTENSIONS
Edited and extended by David Wasserman, Mar 21 2007
STATUS
approved