A200090 Numbers k such that the sum of the distinct prime divisors of k equals three times the largest prime divisor of k.

15015, 45045, 51051, 62985, 72930, 74613, 75075, 105105, 106590, 135135, 145860, 153153, 156009, 165165, 187473, 188955, 190190, 195195, 213180, 218790, 222870, 223839, 225225, 279565, 291720, 314925, 315315, 319770, 335478, 357357, 364650, 375375, 380380

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

15015 is a term because its distinct prime divisors are 3, 5, 7, 11, 13 and their sum 3 + 5 + 7 + 11 + 13 = 39 equals 3*13.

Mathematica

Select[Range[400000], Plus@@(pl=First/@FactorInteger[#])==3*pl[[-1]]&]

Crossrefs

Cf. A006530 (gpf), A008472 (sopf), A200070.

Sequence in context: A335052 A294026 A133778 * A147578 A285993 A295453

Adjacent sequences: A200087 A200088 A200089 * A200091 A200092 A200093

Keyword

nonn

Author

Michel Lagneau, Nov 13 2011

Status

approved