A125903 a(n) = product of the first n primes which are coprime to n.

2, 15, 70, 1155, 6006, 1616615, 1385670, 111546435, 2156564410, 742073813481, 674612557710, 2180460221945005, 1006366256282310, 2327797034085003195, 128184023343614175938, 961380175077106319535, 6899316550553351234310

Offset

1,1

Links

Table of n, a(n) for n=1..17.

Example

The first 6 primes which are coprime to 6 are 5,7,11,13,17,19. So a(6)=5*7*11*13*17*19 = 1616615.

Mathematica

f[n_] := Block[{c = n, k = 0, p, t = 1}, While[c > 0, k++; While[p = Prime[k]; GCD[p, n] > 1, k++ ]; c--; t *= p; ]; t]; Table[f[n], {n, 17}] (* Ray Chandler, Dec 14 2006 *)

Crossrefs

Cf. A119993, A125902.

Sequence in context: A146757 A091135 A056037 * A268644 A178321 A007232

Adjacent sequences: A125900 A125901 A125902 * A125904 A125905 A125906

Keyword

nonn

Author

Leroy Quet, Dec 13 2006

Extensions

Extended by Ray Chandler, Dec 14 2006

Status

approved