Search: id:A120581 Results 1-1 of 1 results found. %I A120581 %S A120581 1,4,64,28672,17825792,24696061952,4398046511104,6413125869375586304, %T A120581 1279761316857673852911616,565738597953418785628899770368, %U A120581 372547299599873882347063111621541888,5264848781000759906705331926184317767647232 %V A120581 1,4,-64,-28672,-17825792,-24696061952,-4398046511104,6413125869375586304, %W A120581 1279761316857673852911616,565738597953418785628899770368, %X A120581 372547299599873882347063111621541888,-5264848781000759906705331926184317767647232 %N A120581 Hankel transform of sum{k=0..n, C(2k,k)*2^k}. %F A120581 a(n)=4^(n+C(n,2))(-1)^n*sum{k=0..n, C(n+k,2k)(-2)^(n-k)}; a(n)=8^n*4^C(n, 2)*sum{k=0..n, C(n+k,2k)(-2)^(-k)}; a(n)=4^n*4^C(n,2)(-1)^n*A087168(n); %Y A120581 Cf. A120580. %Y A120581 Sequence in context: A053763 A053923 A051191 this_sequence A146520 A030176 A033635 %Y A120581 Adjacent sequences: A120578 A120579 A120580 this_sequence A120582 A120583 A120584 %K A120581 easy,sign %O A120581 0,2 %A A120581 Paul Barry (pbarry(AT)wit.ie), Jun 15 2006 Search completed in 0.001 seconds