A123279 a(n) = product of the first n integers from among those positive integers which are coprime to n.

1, 3, 8, 105, 144, 85085, 5760, 2027025, 3203200, 4216455243, 43545600, 29248404810625, 6706022400, 1305433904506875, 1707444076642304, 191898783962510625, 376610217984000, 232876694951587194633125

Offset

1,2

Links

Table of n, a(n) for n=1..18.

Example

The first 4 positive integers which are coprime to 4 are 1,3,5,7. So a(4) = 1*3*5*7 = 105.

Mathematica

f[n_] := Block[{c = n, k = 0, p = 1}, While[c > 0, k++; While[GCD[k, n] > 1, k++ ]; c--; p *= k; ]; p]; Table[f[n], {n, 20}] (* Ray Chandler, Dec 14 2006 *)

Crossrefs

Cf. A069213, A077581, A077582.

Sequence in context: A028504 A349561 A231389 * A361872 A279164 A134803

Adjacent sequences: A123276 A123277 A123278 * A123280 A123281 A123282

Keyword

nonn

Author

Leroy Quet, Dec 11 2006

Extensions

Extended by Ray Chandler, Dec 14 2006

Status

approved