[seqfan] Cannot reproduce A328980
Lars Blomberg
larsl.blomberg at comhem.se
Thu Nov 7 13:49:45 CET 2019
Hello Seqfans,
A328980 - Number of solutions to Erdos's Last Equation in n variables.
Unfortunately, I have no access to the referenced paper, but I infer that
only non-negative x_i are permitted and that solutions with the same
product/sum value are only counted once.
Then I can reproduce n=2,3,4,5 but for n=6,7 the values differ as shown
below.
Regards,
Lars
a(2) = 2
1: (0, 0) 0 0
2: (3, 6) 18 18
3: (4, 4) 16 16
a(3) = 7
1: (0, 0, 0) 0 0
2: (1, 4, 15) 60 60
3: (1, 5, 9) 45 45
4: (1, 6, 7) 42 42
5: (2, 2, 12) 48 48
6: (2, 3, 5) 30 30
7: (3, 3, 3) 27 27
a(4) = 8
1: (0, 0, 0, 0) 0 0
2: (1, 1, 5, 28) 140 140
3: (1, 1, 6, 16) 96 96
4: (1, 1, 7, 12) 84 84
5: (1, 1, 8, 10) 80 80
6: (1, 2, 3, 12) 72 72
7: (1, 2, 4, 7) 56 56
8: (1, 3, 4, 4) 48 48
a(5) = 8
1: (0, 0, 0, 0, 0) 0 0
2: (1, 1, 1, 6, 45) 270 270
3: (1, 1, 1, 7, 25) 175 175
4: (1, 1, 1, 9, 15) 135 135
5: (1, 1, 1, 10, 13) 130 130
6: (1, 1, 2, 3, 35) 210 210
7: (1, 1, 2, 5, 9) 90 90
8: (1, 1, 3, 5, 5) 75 75
a(6) = 16, OEIS has 17
1: (0, 0, 0, 0, 0, 0) 0 0
2: (1, 1, 1, 1, 7, 66) 462 462
3: (1, 1, 1, 1, 8, 36) 288 288
4: (1, 1, 1, 1, 9, 26) 234 234
5: (1, 1, 1, 1, 10, 21) 210 210
6: (1, 1, 1, 1, 11, 18) 198 198
7: (1, 1, 1, 1, 12, 16) 192 192
8: (1, 1, 1, 2, 4, 27) 216 216
9: (1, 1, 1, 2, 5, 15) 150 150
10: (1, 1, 1, 2, 6, 11) 132 132
11: (1, 1, 1, 2, 7, 9) 126 126
12: (1, 1, 1, 3, 3, 18) 162 162
13: (1, 1, 1, 3, 4, 10) 120 120
14: (1, 1, 1, 3, 6, 6) 108 108
15: (1, 1, 2, 2, 4, 6) 96 96
16: (1, 1, 2, 3, 3, 5) 90 90
a(7) = 15, OEIS has 14
1: (0, 0, 0, 0, 0, 0, 0) 0 0
2: (1, 1, 1, 1, 1, 8, 91) 728 728
3: (1, 1, 1, 1, 1, 9, 49) 441 441
4: (1, 1, 1, 1, 1, 10, 35) 350 350
5: (1, 1, 1, 1, 1, 11, 28) 308 308
6: (1, 1, 1, 1, 1, 13, 21) 273 273
7: (1, 1, 1, 1, 1, 14, 19) 266 266
8: (1, 1, 1, 1, 2, 4, 70) 560 560
9: (1, 1, 1, 1, 2, 7, 13) 182 182
10: (1, 1, 1, 1, 3, 3, 35) 315 315
11: (1, 1, 1, 1, 3, 7, 7) 147 147
12: (1, 1, 1, 1, 4, 5, 7) 140 140
13: (1, 1, 1, 2, 2, 2, 63) 504 504
14: (1, 1, 1, 2, 2, 3, 14) 168 168
15: (1, 1, 1, 2, 3, 3, 7) 126 126
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