A164313 LCM of all differences of odd primes up to prime(n).

2, 4, 24, 120, 840, 1680, 5040, 720720, 720720, 24504480, 465585120, 465585120, 465585120, 53542288800, 160626866400, 4658179125600, 288807105787200, 288807105787200, 288807105787200, 10685862914126400, 10685862914126400

Offset

3,1

Comments

That is, we compute the LCM of all differences prime(i)-prime(j) for 1 < j < i <= n.

Links

Table of n, a(n) for n=3..23.

P. Erdős, Some problems on number theory, Analytic and elementary number theory, (Marseille, 1983), Publ. Math. Orsay, 86-1, pp. 53-67, Univ. Paris XI, Orsay, 1986.

P. Erdős, Some problems on number theory, Proceedings of the seventeenth Southeastern international conference on combinatorics, graph theory, and computing (Boca Raton, Fla., 1986 Congr. Numer. 54 (1986), 225-244.

Mathematica

Table[p=Prime[Range[2, n]]; d=Rest[Union[Abs[Flatten[Outer[Plus, p, -p]]]]]; LCM@@d, {n, 3, 30}]

Crossrefs

Sequence in context: A170931 A317999 A371892 * A087981 A002875 A330504

Adjacent sequences: A164310 A164311 A164312 * A164314 A164315 A164316

Keyword

nonn

Author

T. D. Noe, Aug 12 2009

Status

approved