A120300 Numbers k such that 10^k + 11131719 is prime.

2, 12, 16, 17, 30, 40, 41, 42, 60, 110, 12104, 12678

Offset

1,1

Comments

11131719 is the concatenation of 11,13,17,19, the primes between 10 and 20, chosen because they appear on the Ishango prime bone. Notice the consecutive values of 40, 41 and 42 above. Also 10^12678+11131719 and 10^12104+11131719 are probable primes (Fermat and Lucas PRPs) that occur in this sequence.

References

Jason Earls, Red Zen, Lulu Press, NY, 2007, pp. 147-148. ISBN: 978-1-4303-2017-3.

Links

Table of n, a(n) for n=1..12.

Prog

(PARI) for(n=1, 200, if(isprime(10^n+11131719), print1(n", ")))

Crossrefs

Sequence in context: A036499 A107607 A102975 * A089021 A176888 A114974

Adjacent sequences: A120297 A120298 A120299 * A120301 A120302 A120303

Keyword

more,nonn

Author

Jason Earls, May 27 2007

Extensions

a(11)-a(12) from Michael S. Branicky, Mar 27 2023

Status

approved