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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A117783 Total number of palindromic primes in base 7 below 7^n. 5
 3, 3, 9, 9, 50, 50, 204, 204, 1135, 1135, 6086, 6086, 36018, 36018, 216932, 216932, 1306070, 1306070, 8129138, 8129138, 51773946, 51773946, 326701423, 326701423 (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 7) and therefore is composite (not prime). Hence there is no palindromic prime with an even number of digits. LINKS Table of n, a(n) for n=1..24. Eric Weisstein's World of Mathematics, Palindromic Prime. CROSSREFS Partial sums of A117784. Cf. A029975, A117702. Cf. A117772, A117775, A117777, A117779, A117781, A117785, A117787. Sequence in context: A170832 A232281 A223743 * A121445 A327798 A121074 Adjacent sequences: A117780 A117781 A117782 * A117784 A117785 A117786 KEYWORD nonn,base,more AUTHOR Martin Renner, Apr 15 2006 EXTENSIONS a(9)-a(24) from the data at A117784 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 July 17 21:15 EDT 2024. Contains 374377 sequences. (Running on oeis4.)