A329121 Smallest k such that m//A002275(n)//m is prime, where // denotes concatenation, A002275(n) is the n-th repunit (R_n) and m = k+10^(A006519(n)-1).

0, 2, 3, 16, 73, 18, 7, 28, 117, 72, 7, 2, 7, 2, 33, 10, 29, 0, 21, 10, 191, 0, 1133, 30, 79, 20, 81, 58, 19, 2, 57, 116, 77, 108, 79, 48, 97, 40, 1043, 42, 47, 86, 13, 52, 149, 82, 47, 56, 9, 80, 41, 42, 61, 86, 51, 68, 311, 262, 1001, 222, 7, 496, 1367, 12

Offset: 0

Author

Chai Wah Wu, Nov 05 2019

Keywords

• nonn
• base

Comments

a(n) = A263182(n) - 10^(A006519(n)-1). We use the convention that A007814(0) = 0 and A006519(0) = 1.

a(A004023(n)-2) = 0.

Links

• Chai Wah Wu, Table of n, a(n) for n = 0..5007

Crossrefs

Cf. A002275, A004023, A006519, A007814, A263182.