Search: id:A072287 Results 1-1 of 1 results found. %I A072287 %S A072287 1,2,7,47,155,2027,6597,42835,138875,3599155,11654465,75457289, %T A072287 244238477,3161900479,10232916665,66231885067,214336798299, %U A072287 11097918730051,35913975952793,232441522435405,752199270651129 %N A072287 Let f(n, m) = binomial(n - m/2 + 1, n - m + 1) - binomial(n - m/2, n - m + 1) and let s(n) = Sum_{k=0..n} f(n, k); then a(n) = numerator of s(n). %F A072287 s(0)=1, s(1)=2, s(n+1)=s(n)+s(n-1)+binomial(n-1/2, n) for n>=1. %e A072287 1,2,7/2,47/8,155/16,2027/128,6597/256,42835/1024,138875/2048,... %t A072287 f[n_, m_] := Binomial[n - m/2 + 1, n - m + 1] - Binomial[n - m/2, n - m + 1]; s[n_] := Sum[ f[n, k], {k, 0, n}]; Table [Numerator[s[n]], {n, 0, 26}] %Y A072287 Denominator of s(n+1) = A046161(n). %Y A072287 Sequence in context: A062632 A116892 A054555 this_sequence A091117 A056854 A117141 %Y A072287 Adjacent sequences: A072284 A072285 A072286 this_sequence A072288 A072289 A072290 %K A072287 nonn,easy,frac %O A072287 0,2 %A A072287 Michele Dondi (bik.mido(AT)tiscalinet.it), Jul 11, 2002 Search completed in 0.001 seconds