This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A227858 #29 Jun 29 2025 09:16:54 %S A227858 1,2,3,4,5,6,7,8,9,11,22,33,44,55,66,77,88,99,101,111,121,131,141,151, %T A227858 161,171,181,191,202,212,222,232,242,252,262,272,282,292,303,313,323, %U A227858 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 %N A227858 Numbers which start and end with the same digit in decimal. %C A227858 Supersequence of A002113 and A208259. %C A227858 The first term that is not a palindromic number is a(109) = 1011. - _Alonso del Arte_, Nov 01 2013 %C A227858 Primes in this sequence are A077652. - _Jonathan Vos Post_, Nov 02 2013 %C A227858 Differs from A110751 which contains for example 1089. - _R. J. Mathar_, Jun 29 2025 %H A227858 Charles R Greathouse IV, <a href="/A227858/b227858.txt">Table of n, a(n) for n = 1..10000</a> %F A227858 a(n) = 10n + O(1). - _Charles R Greathouse IV_, Nov 01 2013 %t A227858 Select[Range[700],IntegerDigits[#][[1]]==IntegerDigits[#][[-1]]&] (* _Harvey P. Dale_, Nov 28 2019 *) %o A227858 (PARI) is(n)=n=digits(n);n[1]==n[#n] \\ _Charles R Greathouse IV_, Nov 01 2013 %Y A227858 Cf. A002113, A077652, A208259. %K A227858 nonn,easy,base %O A227858 1,2 %A A227858 Brian E. Foose and _Todd R. Haldeman_, Nov 01 2013