This site is supported by donations to The OEIS Foundation.



Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A216907 Smallest palindromic number of length 13 in two bases differing by n. 15
318713056300, 101252880671531, 778061547945037, 8047782883062742, 37866346844745025, 247644110790746909, 828823170233185174, 10556938000726441969, 10175119610486126649, 34575397981277771773, 91506808775956056797 (list; graph; refs; listen; history; text; internal format)



See comments sections of A216840 and A216841.  Smallest of pair of bases are 8, 12, 14, 17, 19, 22, 24, 30, 32.  For the remarkable case a(10), not only does the number have four 7s in a row in base 10, but it also has prime reversal there and in its 2nd base of 13-palindromicity, 42, no digit larger than 20 appears.  A216*** cross-references are others in a collection of sequences that includes this one, while A171*** ones are various record multi-base palindromes.


Table of n, a(n) for n=1..11.


The first term is 4506461646054 in base 8 and 1113578753111 in base 9.


Cf. A171701, A171702, A171703, A171704, A171705, A171706, A171740, A171741, A171742, A171775, A216840, A216841, A216843, A216899, A216900, A216901, A216902, A216903, A216904, A216905, A216906, A216908, A216909, A216910.

Sequence in context: A172785 A172847 A022263 * A186911 A172714 A080132

Adjacent sequences:  A216904 A216905 A216906 * A216908 A216909 A216910




James G. Merickel, Sep 19 2012


a(10) added by James G. Merickel, Oct 17 2012

a(11) from Chai Wah Wu, Aug 20 2015



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

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 13 01:23 EST 2019. Contains 329963 sequences. (Running on oeis4.)