A208768 The distinct values of A070198.

0, 1, 5, 11, 59, 419, 839, 2519, 27719, 360359, 720719, 12252239, 232792559, 5354228879, 26771144399, 80313433199, 2329089562799, 72201776446799, 144403552893599, 5342931457063199, 219060189739591199, 9419588158802421599, 442720643463713815199

Offset

1,3

Comments

The terms of A070198, and duplicates removed.

a(n) = A051451(n) - 1 = A051452(n) - 2.

From Daniel Forgues, Apr 27 2014: (Start)

Factorizations:

5, 11, 59, 419, 839 are primes;

2519 = 11*229, 27719 = 53*523, 360359 = 173*2083,

720719 = 31*67*347, 12252239 = 29*647*653;

232792559, 5354228879 are primes;

26771144399 = 47*12907*44131, 80313433199 = 29*61*45400471;

2329089562799 is prime;

72201776446799 = 37*149*239*1091*50227;

144403552893599 is prime;

Very likely contains an infinite number of primes (see A057824). (End)

A more natural (compare with A051452) name for the sequence: lcm(1, ..., k) - 1, where k is the n-th prime power A000961(n). - Daniel Forgues, May 09 2014

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..250

Prog

(Haskell)
import Data.List (nub)
a208768 n = a208768_list !! (n-1)
a208768_list = nub a070198_list

Crossrefs

Sequence in context: A104357 A104364 A136669 * A057824 A057822 A168243

Adjacent sequences: A208765 A208766 A208767 * A208769 A208770 A208771

Keyword

nonn

Author

Reinhard Zumkeller, Mar 01 2012

Status

approved