

A125903


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


1



2, 15, 70, 1155, 6006, 1616615, 1385670, 111546435, 2156564410, 742073813481, 674612557710, 2180460221945005, 1006366256282310, 2327797034085003195, 128184023343614175938, 961380175077106319535, 6899316550553351234310
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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}] (*Chandler*)


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



