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 A083851 #12 Jun 24 2022 04:44:44 %S A083851 1,2,3,4,5,6,7,8,9,101,111,131,141,151,161,171,181,191,202,212,222, %T A083851 232,252,262,272,282,292,303,313,323,333,343,353,373,383,393,404,414, %U A083851 424,434,444,454,464,474,494,505,515,525,535,545,555,565,575,585,595,606 %N A083851 Decimal palindromes that are not multiples of 11. %C A083851 A083850(a(n)) = 0; all members have odd length. %H A083851 Charles R Greathouse IV, <a href="/A083851/b083851.txt">Table of n, a(n) for n = 1..10000</a> %t A083851 max = 600; Complement[Select[Range[max], IntegerDigits[#] == Reverse[IntegerDigits[#]] &], 11Range[Ceiling[max/11]]] (* _Alonso del Arte_, May 11 2014 *) %o A083851 (PARI) is(n)=n%11 && subst(Polrev(digits(n)), 'x, 10)==n \\ _Charles R Greathouse IV_, May 14 2014 %o A083851 (Python) %o A083851 from itertools import chain, count, islice %o A083851 def A083851_gen(): # generator of terms %o A083851 return filter(lambda n: n % 11,chain.from_iterable((int((s:=str(d))+s[-2::-1]) for d in range(10**l,10**(l+1))) for l in count(0))) %o A083851 A083851_list = list(islice(A083851_gen(),20)) # _Chai Wah Wu_, Jun 23 2022 %Y A083851 Cf. A083852, A002113, A008593. %K A083851 nonn,base %O A083851 1,2 %A A083851 _Reinhard Zumkeller_, May 06 2003