A130041 Take the integers >= 2. If n is the m-th positive integer with k positive divisors, then replace it with the m-th positive integer with (k+1) positive divisors.
4, 9, 6, 25, 16, 49, 81, 8, 625, 121, 64, 169, 2401, 14641, 12, 289, 729, 361, 15625, 28561, 83521, 529, 36, 10, 130321, 279841, 117649, 841, 100, 961, 1771561, 707281, 923521, 1874161, 48, 1369, 2825761, 3418801, 196, 1681, 225, 1849, 4826809
Offset: 2
Keywords
Examples
The number of positive divisors of the integers >= 2 form the sequence 2,2,3,2,4,2,4,3,4,2,6,2,4,4,5,... The number of positive divisors of the terms of {a(j)} form the sequence: 3,3,4,3,5,3,5,4,5,3,7,3,5,5,6,... The n-th term has 1 more divisor than (n+1) has, for every positive integer n. And those terms with the same number of divisors occur in numerical order within {a(j)}.
Comment from _R. J. Mathar_, Oct 15 2007: This searches for n in the following table (paraphrasing A119586) and replaces n by the value in the same column, but the next row:
.....2......3......5......7.....11.....13.....17.....19....
.....4......9.....25.....49....121....169....289....361...
.....6......8.....10.....14.....15.....21.....22.....26...
....16.....81....625...2401..14641..28561..83521.130321....
....12.....18.....20.....28.....32.....44.....45.....50....
....64....729..15625.117649.1771561....
Crossrefs
Cf. A130042.
Extensions
More terms from R. J. Mathar, Oct 15 2007
Comments