A109854 Least K such that K*(3^(n+j))+1 is prime for j=0 to 4.

20, 110, 110, 20980, 29580, 9860, 150780, 50260, 217490, 657770, 426650, 1999330, 2942960, 1295490, 431830, 437570, 436450, 7564120, 6449730

Offset

1,1

Links

Table of n, a(n) for n=1..19.

Example

20*(3^(1+0))+1=61 prime
20*(3^(1+1))+1=181 prime
20*(3^(1+2))+1=541 prime
20*(3^(1+3))+1=1621 prime
20*(3^(1+4))+1=4861 prime
so for n=1 K=20.

Crossrefs

Sequence in context: A232586 A189437 A285698 * A008383 A024192 A309781

Adjacent sequences: A109851 A109852 A109853 * A109855 A109856 A109857

Keyword

nonn

Author

Pierre CAMI, Aug 31 2005

Status

approved