cp's OEIS Frontend

A071992 a(n) = 3*n^2 + 2*n - 4 * Sum_{k=1..n} A003159(k).

%I A071992 #21 Feb 24 2025 22:43:29
%S A071992 1,0,1,4,5,4,1,0,1,0,1,4,5,8,13,16,17,16,17,20,21,20,17,16,17,16,13,8,
%T A071992 5,4,1,0,1,0,1,4,5,4,1,0,1,0,1,4,5,8,13,16,17,16,17,20,21,24,29,32,37,
%U A071992 44,49,52,53,56,61,64,65,64,65,68,69,68,65,64,65,64,65,68,69,72,77,80
%N A071992 a(n) = 3*n^2 + 2*n - 4 * Sum_{k=1..n} A003159(k).
%C A071992 0 <= a(n) <= n for any n.
%H A071992 John Tyler Rascoe, <a href="/A071992/b071992.txt">Table of n, a(n) for n = 1..10241</a>
%H A071992 Robert G. Wilson v, <a href="/A071992/a071992.jpeg">Illustration of initial terms</a>
%F A071992 For any k, a(A062880(k)) = 0.
%F A071992 a(A000695(k)) = A000695(k).
%o A071992 (Python)
%o A071992 def A003159(n): #see A003159
%o A071992     return
%o A071992 def A071992_list(max_n):
%o A071992     A,s = [],0
%o A071992     for n in range(1,max_n+1):
%o A071992         s += A003159(n)
%o A071992         A.append(3*n**2 + 2*n - 4*s)
%o A071992     return A # _John Tyler Rascoe_, Feb 24 2025
%Y A071992 Cf. A000695, A003159, A062880.
%K A071992 easy,nonn
%O A071992 1,4
%A A071992 _Benoit Cloitre_, Jun 17 2002