The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A117777 Total number of palindromic primes in base 4 below 4^n. 5
 2, 3, 6, 6, 16, 16, 45, 45, 142, 142, 435, 435, 1417, 1417, 4802, 4802, 16433, 16433, 57808, 57808, 210708, 210708, 752233, 752233, 2748264, 2748264, 10211513, 10211513, 38013234, 38013234, 140417288, 140417288 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Every palindrome with an even number of digits is divisible by 11 (in base 4) and therefore is composite (not prime). Hence there is only one palindromic prime with an even number of digits. LINKS Table of n, a(n) for n=1..32. Eric Weisstein's World of Mathematics, Palindromic Prime. CROSSREFS Partial sums of A117778. Cf. A029972, A117699. Cf. A117772, A117775, A117779, A117781, A117783, A117785, A117787. Sequence in context: A339546 A007894 A102625 * A371991 A223547 A049297 Adjacent sequences: A117774 A117775 A117776 * A117778 A117779 A117780 KEYWORD nonn,base,more AUTHOR Martin Renner, Apr 15 2006 EXTENSIONS a(13)-a(32) from the data at A117778 added by Amiram Eldar, Mar 21 2021 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 15 11:45 EDT 2024. Contains 375938 sequences. (Running on oeis4.)