cp's OEIS Frontend

A026070 a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2; |s(i) - s(i-1)| <= 1 for i >= 3, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A024996.

%I A026070 #6 Jun 23 2013 09:53:12
%S A026070 1,2,8,24,76,232,707,2136,6429,19282,57695,172316,513955,1531362,
%T A026070 4559271,13566288,40349619,119972214,356634978,1059985776,3150165270,
%U A026070 9361450868,27819215185,82670528056,245680350995,730149455646,2170105711452
%N A026070 a(n) = number of (s(0), s(1), ..., s(n)) such that every s(i) is an integer, s(0) = 0, |s(i) - s(i-1)| = 1 for i = 1,2; |s(i) - s(i-1)| <= 1 for i >= 3, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A024996.
%F A026070 Conjecture: (n+3)*a(n) +(-5*n-6)*a(n-1) +(3*n-11)*a(n-2) +(11*n-8)*a(n-3) +2*(-2*n+17)*a(n-4) +6*(-n+6)*a(n-5)=0. - _R. J. Mathar_, Jun 23 2013
%Y A026070 First differences of A025181. Second differences of A014532.
%K A026070 nonn
%O A026070 3,2
%A A026070 _Clark Kimberling_