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 A064263 #20 Dec 22 2024 20:34:15
%S A064263 0,11,22,3,14,25,6,17,28,9,20,1,12,23,4,15,26,7,18,29,10,21,2,13,24,5,
%T A064263 16,27,8,19,0,11,22,3,14,25,6,17,28,9,20,1,12,23,4,15,26,7,18,29,10,
%U A064263 21,2,13,24,5,16,27,8,19,0,11,22,3,14,25,6,17,28,9,20
%N A064263 a(n) = 11*n mod 30.
%C A064263 Epact in Julian calendar for a year with Golden Number n+1.
%D A064263 B. Blackburn and L. Hollford-Stevens, The Oxford Companion to the Year, Oxford, 1999; see p. 821.
%H A064263 Harry J. Smith, <a href="/A064263/b064263.txt">Table of n, a(n) for n = 0..1000</a>
%H A064263 <a href="/index/Rec#order_30">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
%t A064263 Mod[11*Range[0,80],30] (* _Harvey P. Dale_, Mar 13 2014 *)
%o A064263 (PARI) a(n) = { 11*n % 30 } \\ _Harry J. Smith_, Sep 10 2009
%K A064263 nonn,easy
%O A064263 0,2
%A A064263 _N. J. A. Sloane_, Sep 24 2001