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 A218008 #8 Jun 02 2025 08:10:04 %S A218008 0,0,2,4,10,18,38,68,138,250,502,922,1846,3430,6862,12868,25738,48618, %T A218008 97238,184754,369510,705430,1410862,2704154,5408310,10400598,20801198, %U A218008 40116598,80233198,155117518,310235038 %N A218008 Sum of successive absolute differences of the binomial coefficients = 2*A014495(n). %F A218008 a(n) = sum |C(n,k+1)-C(n,k)|, k=0..n-1 = 2*sum C(n,k+1)-C(n,k), k=0..floor((n-1)/2) = 2*(C(n, floor((n+1)/2)) - 1) %o A218008 (Maxima) A218008(n):=2*(binomial(n,floor((n+1)/2))-1)$ %o A218008 makelist(A218008(n),n,0,30); /* _Martin Ettl_, Nov 01 2012 */ %Y A218008 Cf. Row sums of absolute values of A214292 %K A218008 nonn %O A218008 0,3 %A A218008 _Olivier Gérard_, Oct 18 2012