A137198 - OEIS

A137198

Sarrus numbers that become prime when two is added.

561, 645, 1905, 2465, 4371, 23001, 25761, 60701, 87249, 158369, 181901, 206601, 212421, 253241, 280601, 332949, 348161, 513629, 580337, 587861, 656601, 831405, 1207361, 1275681, 1472505, 1489665, 1678541, 1735841, 1815465, 1909001

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OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

EXAMPLE

561 is a Sarrus number and 563 is prime.

MATHEMATICA

Select[Range[10^5], CompositeQ[#] && PowerMod[2, (# - 1), #] == 1 && PrimeQ[# + 2] &] (* Amiram Eldar, Jun 28 2019 *)

CROSSREFS

Intersection of A001567 and A040976.

Sequence in context: A215672 A085999 A224695 * A194231 A141705 A135721

Adjacent sequences: A137195 A137196 A137197 * A137199 A137200 A137201

KEYWORD

nonn

AUTHOR

Jason Earls, Mar 04 2008

EXTENSIONS

More terms from R. J. Mathar, Apr 01 2008

STATUS

approved