A216840 Smallest palindromic number of 3 digits in two bases differing by n.

46, 26, 121, 109, 157, 211, 209, 197, 257, 307, 381, 576, 463, 676, 601, 701, 757, 842, 929, 1086, 1123, 1445, 1333, 1717, 1297, 1801, 1522, 2092, 1765, 2393, 2026, 2026, 2305, 2696, 2501, 2701, 2757, 2971, 3133, 3600, 3421, 3718, 4411, 3845, 4551, 4031, 4691

Offset

1,1

Comments

This is one of a collection of sequences of doubly palindromic numbers of same lengths in each of two bases. The lengths go from 2 through 17, excluding 16 (only one term available at present), and the order of the first two of these are switched in terms of their A-numbers. These are the A216*** cross-references. The 171*** c-refs are to a variety of record multiple-base palindromes. Larger comments are to be found -- will generally be -- in the 2-palindrome sequence. The smaller bases of a pair here are (in sequence) 4, 3, 6, 5, 6, 7, 6, 6, 7, 7.

Links

Chai Wah Wu, Table of n, a(n) for n = 1..10000

Example

The first entry here, 46 in base 10, is represented as 222 in base 4 and 141 in base 5. The 2nd entry here, 26 in base 10, is represented as 222 in base 3 and 101 in base 5. The next is then the smallest in bases that differ by 3, bases 6 and 9 by what is in the comment.
a(3) = 121 is 232 in base 7, a(5) = 157 is 313 in base 7 and 111 in base 12, a(6) = 211 is 323 in base 8 and 111 in base 14. - Chai Wah Wu, Aug 19 2015

Crossrefs

Cf. A171701, A171702, A171703, A171704, A171705, A171706, A171740, A171741, A171742, A171775, A216841, A216843, A216899, A216900, A216901, A216902, A216903, A216904, A216905, A216906, A216907, A216908, A216909, A216910.

Sequence in context: A033366 A097927 A033978 * A060958 A094892 A258915

Adjacent sequences: A216837 A216838 A216839 * A216841 A216842 A216843

Keyword

nonn,base

Author

James G. Merickel, Sep 19 2012

Extensions

More terms and corrected a(3), a(5) and a(6) by Chai Wah Wu, Aug 19 2015

Status

approved