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A123279 a(n) = product of the first n integers from among those positive integers which are coprime to n. 0
1, 3, 8, 105, 144, 85085, 5760, 2027025, 3203200, 4216455243, 43545600, 29248404810625, 6706022400, 1305433904506875, 1707444076642304, 191898783962510625, 376610217984000, 232876694951587194633125 (list; graph; refs; listen; history; text; internal format)
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: A066619 A028504 A231389 * A279164 A134803 A030063

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

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Last modified October 19 16:25 EDT 2021. Contains 348091 sequences. (Running on oeis4.)