A098515 Least m such that m and m+n are both products of exactly n primes counting multiplicity.

1, 2, 4, 27, 36, 675, 810, 12393, 7552, 268992, 506240, 6436341, 2440692, 290698227, 455503986, 4897228800, 520575984, 519417147375, 124730265582, 8961777270765, 753891573760, 203558860750848, 51126160064490, 4021771417157632, 1305269217263592, 69131417822953472, 57710779788427264, 1838459534098563045, 63846774162325476

Offset: 1

Author

Robert G. Wilson v, Sep 11 2004

Keywords

• nonn

Examples

			4=2*2 & 6=2*3; 27=3*3*3 & 30=2*3*5; 36=2*2*3*3 & 40=2*2*2*5; 675=3*3*3*5*5 & 680=2*2*2*5*17; 810=2*3*3*3*3*5 and 816=2*2*2*2*3*17; etc.
		

Crossrefs

Cf. A097978.

Cf. A097978, A135058.

Programs

Mathematica

f[n_Integer] := Plus @@ Transpose[FactorInteger[n]][[2]]; g[n_] := (k = 2^n; While[a = f[k]; b = f[k + n]; a != b || a != n, k++ ]; k); Do[ Print[ g[n]], {n, 12}]

Extensions

More terms from David Wasserman, Feb 20 2008