cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A244114 Prime lucky numbers that are palindromic in base 2.

Original entry on oeis.org

3, 7, 31, 73, 127, 1831, 1879, 5869, 6211, 8191, 19609, 25939, 28123, 86293, 86677, 88117, 97213, 98563, 98947, 115783, 131071, 268993, 287281, 296713, 321721, 354997, 456571, 505711, 514783, 524287, 1096609, 1199689, 1242601, 1415989, 1420981, 1488301, 1672243, 1741099, 1851271
Offset: 1

Views

Author

Robert G. Wilson v, Jun 20 2014

Keywords

Crossrefs

Intersection of A000040, A000959 & A006995.
Cf. A031881.

Programs

  • Mathematica
    nn = 10^7; t = Range[1, nn, 2]; sieve[n_] := Module[{k = t[[n]]}, t = Delete[t, Table[{i}, {i, k, Length[t], k}]]]; n = 1; While[ t[[n]] < Length[t], n++; sieve[n]]; palQ[n_Integer, base_Integer] := Module[{idn = IntegerDigits[n, base]}, idn == Reverse[ idn]]; Select[t, PrimeQ@# && palQ[#, 2] &]

A309375 Unlucky palindromic primes.

Original entry on oeis.org

2, 5, 11, 101, 131, 181, 191, 313, 353, 373, 383, 757, 797, 919, 929, 10301, 10601, 11311, 11411, 12421, 12721, 12821, 13331, 13931, 14341, 14741, 15451, 15551, 16061, 16361, 16561, 16661, 17471, 17971, 18481, 19391, 19891, 19991, 30203, 30403, 30703, 30803
Offset: 1

Views

Author

Hauke Löffler, Jul 26 2019

Keywords

Examples

			a(1) = 2 because 2 is both a palindromic prime (A002385) and an unlucky number (A050505).
		

Crossrefs

Intersection of A002385 and A050505.
Cf. A031881.

Programs

Extensions

4 wrong terms removed and more terms added by Amiram Eldar, May 14 2023
Showing 1-2 of 2 results.