A086554 - OEIS

A086554

a(1) = 1; for n>1, a(n) = smallest number not included earlier such that each P+1 is prime, where P is the product of an (n-1)-set from the previous n terms.

1, 2, 6, 23, 370, 1056, 36695, 491942, 23005823

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OFFSET

1,2

COMMENTS

Conjecture: sequence is finite.

No more terms < 166890000. - David Wasserman, Apr 19 2005

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

a(4) = 23 as 1*2*6+1, 2*6*23+1, 1*6*23+1 and 1*2*23+1 (i.e. 13, 277, 139 and 47) all are primes.

CROSSREFS

Sequence in context: A364791 A020122 A327426 * A213324 A007672 A322255

Adjacent sequences: A086551 A086552 A086553 * A086555 A086556 A086557

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Aug 29 2003

EXTENSIONS

Corrected and extended by David Wasserman, Apr 19 2005

STATUS

approved