cp's OEIS Frontend

A025181 a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is an integer, s(0) = 0, |s(1)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A025177.

%I A025181 #6 Feb 25 2015 15:52:29
%S A025181 1,3,11,35,111,343,1050,3186,9615,28897,86592,258908,772863,2304225,
%T A025181 6863496,20429784,60779403,180751617,537386595,1597372371,4747537641,
%U A025181 14108988509,41928203694,124598731750,370279082745,1100428538391,3270534249843
%N A025181 a(n) = number of (s(0), s(1), ..., s(n)) such that s(i) is an integer, s(0) = 0, |s(1)| = 1, |s(i) - s(i-1)| <= 1 for i >= 2, s(n) = 3. Also a(n) = T(n,n-3), where T is the array defined in A025177.
%F A025181 Conjecture: +(n+3)*a(n) +(-5*n-7)*a(n-1) +(3*n-7)*a(n-2) +(11*n-7)*a(n-3) +4*(-n+6)*a(n-4) +6*(-n+5)*a(n-5)=0. - _R. J. Mathar_, Feb 25 2015
%F A025181 Conjecture: -(n+3)*(n-3)*(4*n^2-12*n+17)*a(n) +(n-1)*(8*n^3-20*n^2+30*n-81)*a(n-1) +3*(n-1)*(n-2)*(4*n^2-4*n+9)*a(n-2)=0. - _R. J. Mathar_, Feb 25 2015
%Y A025181 Cf. A025568.
%Y A025181 First differences of A014532. First differences are in A026070.
%K A025181 nonn
%O A025181 3,2
%A A025181 _Clark Kimberling_