Search: id:A141222 Results 1-1 of 1 results found. %I A141222 %S A141222 1,5,22,95,406,1722,7260,30459,127270,529958,2200276,9111830,37650172, %T A141222 155266100,639191160,2627302995,10784089350,44208873390,181025067300, %U A141222 740483276610,3026059513620,12355464845100 %N A141222 Expansion of (sqrt(1-4x)*(1-4x+4x^2)-16x^2+8x-1)/(2x*(1-4x^2)). %C A141222 Apply Riordan array (1/sqrt(1-4x), xc(x)) to A131056, c(x) the g.f. of A000108. %C A141222 Apply Riordan array (c(x)/sqrt(1-4*x),x*c(x)^2) to A131055. %C A141222 Hankel transform appears to be (-1)^n*A085046(n). %F A141222 a(n)=sum{k=0..n, (1+(k+1)2^(k-1)-0^k/2)*C(2n-k,n-k)}; a(n)=sum{k=0..n, C(2n,k)*C(n+1,2n-k)}; %Y A141222 Sequence in context: A128746 A049675 A053154 this_sequence A127360 A116415 A026861 %Y A141222 Adjacent sequences: A141219 A141220 A141221 this_sequence A141223 A141224 A141225 %K A141222 easy,nonn %O A141222 0,2 %A A141222 Paul Barry (pbarry(AT)wit.ie), Jun 14 2008 Search completed in 0.001 seconds