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A132996 a(n) = gcd(Sum_{k=1..n} c(k), Product_{j=1..n} c(j)), where c(k) is the k-th composite. 0
4, 2, 6, 27, 1, 1, 63, 6, 2, 112, 12, 9, 175, 1, 224, 250, 1, 5, 5, 1, 400, 14, 7, 5, 3, 6, 2, 8, 12, 3, 17, 847, 896, 22, 1, 1, 1, 6, 2, 1, 3, 3, 1, 2, 6, 31, 1, 1, 26, 4, 28, 2, 1, 1, 10, 2368, 2448, 9, 7, 2695, 20, 2, 1, 1, 31, 18, 2, 1, 9, 3596, 52, 10, 1, 1, 1, 5, 4300, 2, 74, 4624 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..80.

EXAMPLE

The first 8 composites are 4,6,8,9,10,12,14,15. 4+6+8+9+10+12+14+15 = 78 = 2*3*13. So a(8) = gcd(2*3*13, 4*6*8*9*10*12*14*15) = 6.

CROSSREFS

Cf. A053767, A036691.

Sequence in context: A019104 A019119 A019181 * A019182 A019105 A183399

Adjacent sequences:  A132993 A132994 A132995 * A132997 A132998 A132999

KEYWORD

nonn

AUTHOR

Leroy Quet, Nov 22 2007

EXTENSIONS

More terms from R. J. Mathar, Jan 13 2008

STATUS

approved

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Last modified June 30 18:15 EDT 2022. Contains 354945 sequences. (Running on oeis4.)