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A208892
Two distinct sets of n consecutive numbers with identical corresponding prime signatures.
3
2, 3, 6, 7, 10, 11, 11, 12, 13, 17, 18, 19, 68, 69, 70, 71, 76, 77, 78, 79, 130, 131, 132, 133, 134, 138, 139, 140, 141, 142, 88, 89, 90, 91, 92, 93, 232, 233, 234, 235, 236, 237, 658, 659, 660, 661, 662, 663, 664, 1090, 1091, 1092, 1093, 1094, 1095, 1096
OFFSET
1,1
COMMENTS
The sets are chosen to minimize the larger of the two start values, so for example, (6,7) and (10,11) would be chosen over (5,6) and (13,14) since 10 is less than 13.
The sequence can be read as follows:
2, 3,
6,7, 10,11,
11,12,13, 17,18,19,
68,69,70,71, 76,77,78,79,
130,131,132,133,134, 138,139,140,141,142
88,89,90,91,92,93, 232,233,234,235,236,237
658,659,660,661,662,663,664, 1090,1091,1092,1093,1094,1095,1096
etc
EXAMPLE
At n=4, the consecutive numbers 68, 69, 70, and 71 have the same prime signature as 76, 77, 78, and 79. Both have the form p^2*q, p*q, p*q*r, and p, respectively.
CROSSREFS
Cf. A046523 (smallest number with same prime signature as n).
Sequence in context: A006877 A328832 A263881 * A085397 A307414 A073439
KEYWORD
nonn,tabf
AUTHOR
Matthijs Coster, Mar 03 2012
STATUS
approved