# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a120171 Showing 1-1 of 1 %I A120171 #11 Dec 26 2023 15:34:48 %S A120171 2,2,3,3,4,5,6,7,8,10,12,14,17,20,24,29,35,42,50,60,72,87,104,125,150, %T A120171 180,216,259,311,373,448,537,645,774,929,1114,1337,1605,1926,2311, %U A120171 2773,3328,3993,4792,5750,6900,8280,9936,11923,14308,17170,20604,24724,29669 %N A120171 a(n) = 2 + floor((1 + Sum_{j=1..n-1} a(j))/5) %H A120171 G. C. Greubel, Table of n, a(n) for n = 1..10000 %t A120171 f[s_] := Append[s, Floor[(11 + Plus @@ s)/5]]; Nest[f, {2}, 53] (* _Robert G. Wilson v_, Jul 08 2006 *) %o A120171 (Magma) %o A120171 function f(n, a, b) %o A120171 t:=0; %o A120171 for k in [1..n-1] do %o A120171 t+:= a+Floor((b+t)/5); %o A120171 end for; %o A120171 return t; %o A120171 end function; %o A120171 g:= func< n, a, b | f(n+1, a, b)-f(n, a, b) >; %o A120171 A120171:= func< n | g(n, 2, 1) >; %o A120171 [A120171(n): n in [1..60]]; // _G. C. Greubel_, Dec 25 2023 %o A120171 (SageMath) %o A120171 @CachedFunction %o A120171 def f(n, p, q): return p + (q +sum(f(k, p, q) for k in range(1, n)))//5 %o A120171 def A120171(n): return f(n, 2, 1) %o A120171 [A120171(n) for n in range(1, 61)] # _G. C. Greubel_, Dec 25 2023 %Y A120171 Cf. A073941, A072493, A112088. %K A120171 nonn %O A120171 1,1 %A A120171 _Graeme McRae_, Jun 10 2006 %E A120171 More terms from _Robert G. Wilson v_, Jul 08 2006 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE