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A082276 Smallest number whose digits can be permuted to get exactly n distinct palindromes. 0
1, 101, 1001, 10001, 100001, 112233, 10000001, 100122, 10000111 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Note that 10^n + 1 is always an upper bound.

a(12) = 1000122, a(18) = 10000122, a(30) = 10012233; probably a(24) = 11223344. Any number C(i+j,j) is the number of palindromes from 2i 1's and 2j 2's, so in particular a(10) <= 1111112222 and a(15) <= 111111112222. If a number in this sequence has an odd number of digits, the odd digit must be 0 or 1, with all other digits in pairs; if the number of digits is even, all must be in pairs. The counts of the nonzero digits must be monotonically decreasing (i.e., at least as many 1's as 2's, etc.) - Franklin T. Adams-Watters, Oct 26 2006

LINKS

Table of n, a(n) for n=1..9.

EXAMPLE

101 gives two palindromes 101 and 011 = 11 hence a(2) = 101.

a(6) = 112233, The digit permutation gives six palindromes 123321,132231,213312,231132,312213,321123.

CROSSREFS

Cf. A082274, A082275.

Sequence in context: A242138 A171764 A164842 * A069597 A139535 A139536

Adjacent sequences:  A082273 A082274 A082275 * A082277 A082278 A082279

KEYWORD

base,more,nonn

AUTHOR

Amarnath Murthy, Apr 13 2003

EXTENSIONS

More terms from Franklin T. Adams-Watters, Oct 26 2006

STATUS

approved

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Last modified October 20 07:17 EDT 2018. Contains 316378 sequences. (Running on oeis4.)