A119351 Indices k of prime palindromic numbers formed by taking k digits in the decimal expansion of Pi and reflecting about the last digit.

1, 2, 27, 151, 461, 2056

Offset: 1

Author

Eric W. Weisstein, May 15 2006; corrected May 27 2006

Keywords

• nonn
• more
• base

Comments

The primes corresponding to these indices are A039954.

a(7) > 50000. - Michael S. Branicky, Feb 11 2025

Examples

			Of 3, 313, 31413, 3141413, 314151413, the first and second are primes, so the first two terms are 1 and 2.
		

Links

• Shyam Sunder Gupta, Mystery of pi, Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 19, 473-497.

Crossrefs

Cf. A039954.