A376246
a(n) is the numerator of Sum_{k = 1..n} 1 / (A376244(k) * A376245(k)).
Original entry on oeis.org
1, 7, 47, 109, 823, 4757, 7582661, 3026164178509, 277505140475561534945603, 260165888480949800316206335248860247693882947, 1735545885361077128120249087863835952607412447268583818069629193850545735375261166814107
Offset: 1
A376247
a(n) is the denominator of Sum_{k = 1..n} 1 / (A376244(k) * A376245(k)).
Original entry on oeis.org
3, 12, 60, 120, 840, 4760, 7582680, 3026164178520, 277505140475561534945640, 260165888480949800316206335248860247693882960, 1735545885361077128120249087863835952607412447268583818069629193850545735375261166814160
Offset: 1
A376244
Lexicographically earliest sequence of positive integers a(1), a(2), ... with the property that the lexicographically earliest sequence of positive integers b(1), b(2), ... such that for any n > 0, S(n) = Sum_{k = 1..n} 1 / (a(k)*b(k)) < 1, also implies that S(n) is never of the form (e_n - 1) / e_n for some integer e_n.
Original entry on oeis.org
3, 4, 5, 4, 7, 3, 9, 1, 11, 4, 13, 7, 9, 19, 10, 2, 23, 25, 29, 27, 53, 1, 17, 7, 2, 2, 15, 67, 22, 37
Offset: 1
The initial terms are:
n a(n) b(n) S(n)
- ---- ------ ---------------------------
1 3 1 1/3
2 4 1 7/12
3 5 1 47/60
4 4 2 109/120
5 7 2 823/840
6 3 17 4757/4760
7 9 177 7582661/7582680
8 1 399089 3026164178509/3026164178520
Showing 1-3 of 3 results.
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