A053559 Primes formed by concatenating n consecutive increasing numbers starting with a palindrome and ending with the next consecutive palindrome.

23, 67, 89, 131132133134135136137138139140141

Offset: 1

Author

G. L. Honaker, Jr., Jan 16 2000

Keywords

• base
• nonn

Comments

The next term, a(5) = 90809...90909, has 505 digits. - M. F. Hasler, Sep 11 2018

Crossrefs

Cf. A000040, A002113.

Programs

PARI

P=1; until(, N=P; for(x=1+P, P=A262038(1+P), N=N*10^(logint(x, 10)+1)+x); ispseudoprime(N)&& print(N",")) \\ M. F. Hasler, Sep 11 2018