A227858 Numbers which start and end with the same digit in decimal.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 202, 212, 222, 232, 242, 252, 262, 272, 282, 292, 303, 313, 323, 333, 343, 353, 363, 373, 383, 393, 404, 414, 424, 434, 444, 454, 464, 474, 484, 494, 505, 515, 525, 535, 545, 555, 565, 575, 585, 595, 606, 616, 626

Offset: 1

Author

Brian E. Foose and Todd R. Haldeman, Nov 01 2013

Keywords

• nonn
• easy
• base

Comments

Supersequence of A002113 and A208259.

The first term that is not a palindromic number is a(109) = 1011. - Alonso del Arte, Nov 01 2013

Primes in this sequence are A077652. - Jonathan Vos Post, Nov 02 2013

Differs from A110751 which contains for example 1089. - R. J. Mathar, Jun 29 2025

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A002113, A077652, A208259.

Programs

Mathematica

Select[Range[700],IntegerDigits[#][[1]]==IntegerDigits[#][[-1]]&] (* Harvey P. Dale, Nov 28 2019 *)

PARI

is(n)=n=digits(n);n[1]==n[#n] \\ Charles R Greathouse IV, Nov 01 2013

Formula

a(n) = 10n + O(1). - Charles R Greathouse IV, Nov 01 2013