A176833 Smallest prime p = prime(i) such that concatenation q(i) = 13//0_(k)//prime(i) (k = 0, 1, 2, ...) is prime.

7, 3, 3, 3, 151, 61, 7, 3, 19, 3, 109, 109, 19, 19, 37, 409, 109, 97, 61, 19, 73, 109, 139, 139, 619, 31, 127, 31, 193, 3, 43, 19, 337, 7, 73, 367, 109, 373, 139, 139

Offset

1,1

Comments

See comments in A176781

Necessarily p = 3 or p of form 3 * n + 1

In recreational mathematics some authors call a prime that is composed of mostly naughts, i.e. zeros, a naughty prime

Links

Table of n, a(n) for n=1..40.

Example

q(0) = 13//7 = 137 = prime(33), 7 = prime(4) is 1st term
q(1) = 13//0//3 = 1303 = prime(213), 3 = prime(2) is 2nd term
q(26) = 13000000000000000000000000031 is a palindromic prime

Crossrefs

A164968, A173291, A176316, A176781

Sequence in context: A135041 A021581 A265411 * A154019 A011299 A225453

Adjacent sequences: A176830 A176831 A176832 * A176834 A176835 A176836

Keyword

base,nonn

Author

Eva-Maria Zschorn (e-m.zschorn(AT)zaschendorf.km3.de), Apr 27 2010

Status

approved