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A074798
Floor of S*n^2, where S equals sum of reciprocal terms of this same sequence.
0
1, 5, 13, 23, 36, 52, 72, 94, 119, 147, 178, 211, 248, 288, 331, 376, 425, 476, 531, 588, 649, 712, 778, 847, 919, 994, 1072, 1153, 1237, 1324, 1414, 1507, 1602, 1701, 1803, 1907, 2014, 2125, 2238, 2354, 2474, 2596, 2721, 2849, 2980, 3114, 3251, 3391, 3533
OFFSET
1,2
FORMULA
a(n) = floor(S*n^2), where S = Sum_{k>=1} 1/a(k).
EXAMPLE
a(10) = 147 because a(10) = floor(S*10^2), where S = 1/1 + 1/5 + 1/13 + 1/23 + 1/36 + 1/52 + 1/72 +... + 1/a(k) +... {k=1..inf}.
S = 1.471869231468455847281... This should be good to about 20 digits. - David Einstein
CROSSREFS
Sequence in context: A125830 A049882 A108195 * A031336 A099958 A213483
KEYWORD
nonn,easy
AUTHOR
Paul D. Hanna, Sep 08 2002
STATUS
approved