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 A029960 #30 Jun 14 2024 12:17:39
%S A029960 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,16,32,48,64,80,96,112,128,144,160,
%T A029960 176,192,208,224,226,241,256,271,286,301,316,331,346,361,376,391,406,
%U A029960 421,436,452,467,482,497,512,527,542,557,572,587,602,617
%N A029960 Numbers that are palindromic in base 15.
%C A029960 Cilleruelo, Luca, & Baxter prove that this sequence is an additive basis of order (exactly) 3. - _Charles R Greathouse IV_, May 04 2020
%H A029960 John Cerkan, <a href="/A029960/b029960.txt">Table of n, a(n) for n = 1..10000</a>
%H A029960 Javier Cilleruelo, Florian Luca and Lewis Baxter, <a href="https://doi.org/10.1090/mcom/3221">Every positive integer is a sum of three palindromes</a>, Mathematics of Computation, Vol. 87, No. 314 (2018), pp. 3023-3055, <a href="http://arxiv.org/abs/1602.06208">arXiv preprint</a>, arXiv:1602.06208 [math.NT], 2017.
%H A029960 Patrick De Geest, <a href="http://www.worldofnumbers.com/nobase10.htm">Palindromic numbers beyond base 10</a>.
%H A029960 Phakhinkon Phunphayap and Prapanpong Pongsriiam, <a href="https://doi.org/10.13140/RG.2.2.23202.79047">Estimates for the Reciprocal Sum of b-adic Palindromes</a>, 2019.
%H A029960 <a href="/index/Ab#basis_03">Index entries for sequences that are an additive basis</a>, order 3.
%F A029960 Sum_{n>=2} 1/a(n) = 3.66254285... (Phunphayap and Pongsriiam, 2019). - _Amiram Eldar_, Oct 17 2020
%t A029960 f[n_,b_]:=Module[{i=IntegerDigits[n,b]},i==Reverse[i]];lst={};Do[If[f[n,15],AppendTo[lst,n]],{n,7!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jul 08 2009 *)
%t A029960 Select[Range@ 620, PalindromeQ@ IntegerDigits[#, 15] &] (* _Michael De Vlieger_, May 13 2017, Version 10.3 *)
%o A029960 (PARI) isok(n) = my(d=digits(n, 15)); d == Vecrev(d); \\ _Michel Marcus_, May 14 2017
%o A029960 (Python)
%o A029960 from sympy import integer_log
%o A029960 from gmpy2 import digits
%o A029960 def A029960(n):
%o A029960 if n == 1: return 0
%o A029960 y = 15*(x:=15**integer_log(n>>1,15)[0])
%o A029960 return int((c:=n-x)*x+int(digits(c,15)[-2::-1]or'0',15) if n<x+y else (c:=n-y)*y+int(digits(c,15)[-1::-1]or'0',15)) # _Chai Wah Wu_, Jun 14 2024
%Y A029960 Palindromes in bases 2 through 14: A006995, A014190, A014192, A029952, A029953, A029954, A029803, A029955, A002113, A029956, A029957, A029958, A029959.
%K A029960 nonn,base,easy
%O A029960 1,3
%A A029960 _Patrick De Geest_