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 A182455 #17 Apr 15 2025 14:57:43 %S A182455 1,3,12,10,24,21,40,36,60,55,84,78,112,105,144,136,180,171,220,210, %T A182455 264,253,312,300,364,351,420,406,480,465,544,528,612,595,684,666,760, %U A182455 741,840,820,924,903,1012,990,1104,1081,1200,1176,1300,1275,1404 %N A182455 a(0)=1, a(n) = (a(n-1) mod (n+2))*(n+2). %H A182455 Reinhard Zumkeller, <a href="/A182455/b182455.txt">Table of n, a(n) for n = 0..10000</a> %F A182455 a(0)=1, a(n) = (a(n-1) mod (n+2))*(n+2). %F A182455 For k>0, a(2*k)=(k+1)*(2*k+4), a(2*k+1)=(k+1)*(2*k+3). %e A182455 a(5) = (a(4) mod 7)*7 = (24 mod 7)*7 = 3*7 = 21. %o A182455 (Python) %o A182455 a=1 %o A182455 for n in range(1,55): %o A182455 print(a, end=', ') %o A182455 a = (a%(n+2)) * (n+2) %o A182455 (Haskell) %o A182455 a182455 n = a182455_list !! n %o A182455 a182455_list = 1 : zipWith (*) (zipWith mod a182455_list [3..]) [3..] %o A182455 -- _Reinhard Zumkeller_, May 01 2012 %Y A182455 Cf. A093005 (a(n)=(a(n-1) mod (n+1))*(n+1)). %K A182455 nonn,easy %O A182455 0,2 %A A182455 _Alex Ratushnyak_, Apr 30 2012