A222729 Palindromic composite numbers starting with a digit 9.

9, 99, 909, 939, 949, 959, 969, 979, 989, 999, 9009, 9119, 9229, 9339, 9449, 9559, 9669, 9779, 9889, 9999, 90009, 90109, 90209, 90309, 90409, 90509, 90609, 90809, 90909, 91119, 91219, 91319, 91419, 91519, 91619, 91719, 91819, 91919, 92029, 92129, 92229, 92329

Offset

1,1

Comments

Subsequence of A032350 (palindromic nonprime numbers) and A002113 (palindromic numbers). Complement of A128375 (palindromic primes starting with a digit 9) with respect to A043044 (palindromic numbers starting with a digit 9).

Links

Jaroslav Krizek, Table of n, a(n) for n = 1..1050

Mathematica

Select[Range[100000], PalindromeQ[#]&&CompositeQ[#]&&IntegerDigits[#][[1]] == 9&] (* Harvey P. Dale, Oct 09 2021 *)

Crossrefs

Cf. A032350, A002113, A128375, A043044.

Sequence in context: A359078 A100681 A043044 * A069000 A250603 A221579

Adjacent sequences: A222726 A222727 A222728 * A222730 A222731 A222732

Keyword

nonn,base

Author

Jaroslav Krizek, Mar 03 2013

Status

approved