A201644
The first of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 11, 15, 35, 45, 231
Offset: 1
1/3+1/5+1/7+1/9+1/11+1/15+1/35+1/45+1/231 = 1.
- R. K. Guy, Unsolved Problems in Number Theory (UPINT), Section D11.
A201646
The second of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 11, 15, 21, 135, 10395
Offset: 1
- R. K. Guy, Unsolved Problems in Number Theory (UPINT), Section D11.
A201648
The fourth of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 11, 15, 21, 231, 315
Offset: 1
- R. K. Guy, Unsolved Problems in Number Theory (UPINT), Section D11.
A201649
The fifth of the five known sets of nine distinct odd numbers the sum of whose reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 11, 15, 33, 45, 385
Offset: 1
- R. K. Guy, Unsolved Problems in Number Theory (UPINT), Section D11.
A201643
John Leech's example of a set of eleven distinct odd numbers the sum of whose reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 15, 21, 27, 35, 63, 105, 135
Offset: 1
- R. K. Guy, Unsolved Problems in Number Theory (UPINT), Section D11.
A211118
One of 17 possible sets of eleven numbers of the form 3^alpha 5^beta 7^gamma whose sum of reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 15, 21, 25, 27, 75, 125, 23625
Offset: 1
A211134
One of 17 possible sets of eleven numbers of the form 3^alpha 5^beta 7^gamma whose sum of reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 15, 21, 27, 35, 45, 105, 945
Offset: 1
- R. Arce-Nazario, F. Castro, and R. Figueroa, On the number of solutions of Sum_{i = 1..11} 1/x_i = 1 in distinct odd natural numbers, J. Number Theory, 133 (2013), pp. 2036-2046.
- Nechemia Burshtein, All the solutions of the equation Sum_{i=1..11} 1/x_i = 1 in distinct integers of the form x_i = 3^alpha 5^beta 7^gamma, Disc. Math. (2008) Vol. 308, No. 18, 4286-4292. MR2427761 (2009e:11061)
A211132
One of 17 possible sets of eleven numbers of the form 3^alpha 5^beta 7^gamma whose sum of reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 15, 21, 27, 35, 45, 135, 315
Offset: 1
A211135
One of 15 possible sets of eleven odd numbers, not all of the form 3^alpha 5^beta 7^gamma, whose sum of reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 15, 11, 33, 35, 45, 55, 77, 105
Offset: 1
A211139
One of 15 possible sets of eleven odd numbers, not all of the form 3^alpha 5^beta 7^gamma, whose sum of reciprocals is 1.
Original entry on oeis.org
3, 5, 7, 9, 13, 19, 21, 35, 315, 325, 1425
Offset: 1
Showing 1-10 of 29 results.
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