A213341 Smallest palindrome with digital root n and n + 1 decimal digits.

0, 55, 686, 6996, 79897, 799997, 8998998, 89999998, 999989999, 9999999999

Offset

0,2

Comments

Formula a(n) = (44/9*(10^n-1)+(10^n+1)*n) gives for n=0 ... 5 another sequence of palindromic terms a(0) = 0, a(1) = 55, a(2) = 686, a(3) = 7887, a(4) = 88888, a(5) = 988889 (which do not fully comply with the definition "smallest palindrome with digital root n and n+1 decimal digits" - because for n = 3, 4, 5 the terms are not the smallest ones possible).

Links

Table of n, a(n) for n=0..9.

Example

a(1) = 55 because there is no smaller two digit palindrome with a digital root of 1.

Crossrefs

Subsequence of A062388.

Sequence in context: A119226 A219928 A226543 * A132155 A173377 A053138

Adjacent sequences: A213338 A213339 A213340 * A213342 A213343 A213344

Keyword

nonn,base,fini,full

Author

Alexander R. Povolotsky, Jun 09 2012

Status

approved