

A093484


Beginning with 2, a(n+1) is obtained as the least prime of the form a(n)*(m)*(m+1)*(m+2)...(m+k) +1 where a(n) was obtained as the least prime of the form a(n1)*(r)*(r+1)*(r+2)...(m1) +1 and so on.


0



2, 5, 61, 1831, 1218127681, 20911135539110754710115844300800001, 205118220637830114524967273372102004176647676497164400621440204800001, 6306868169346727750558231922137388394069771110701510995102537435289737085359877256031030165504001
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OFFSET

1,1


COMMENTS

Product [{a(k)1}/{a(k1)}]= 2*3*4*5*... for k = 2,3,4,... {(51)/2}*{(611)/5}*{(18311)/61}*... = {2}*{3*4}*{5*6}*....
Some of the larger entries may only correspond to probable primes.
The Magma Calculator (http://magma.maths.usyd.edu.au/calc/) confirms that all terms given above through a(8) are, in fact, prime.  Jon E. Schoenfield, Aug 24 2009


LINKS

Table of n, a(n) for n=1..8.


EXAMPLE

a(2) = 2*2 + 1 = 5, a(3) = 5*(3*4) + 1 = 61, a(4) = 61*(5*6) + 1 = 1831.


CROSSREFS

Sequence in context: A004150 A062642 A294528 * A250195 A041069 A217053
Adjacent sequences: A093481 A093482 A093483 * A093485 A093486 A093487


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Apr 14 2004


EXTENSIONS

More terms from Joshua Zucker, Jul 24 2006


STATUS

approved



