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

1,1

Comments

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

Links

Table of n, a(n) for n=1..4.

Prog

(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

Crossrefs

Cf. A000040, A002113.

Sequence in context: A241212 A052087 A030458 * A322414 A031376 A069173

Adjacent sequences: A053556 A053557 A053558 * A053560 A053561 A053562

Keyword

base,nonn

Author

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

Status

approved