Search: id:A156171 Results 1-1 of 1 results found. %I A156171 %S A156171 1,1,3,11,53,357,3521,51665,1122135,35638903,1639453459,108526044099, %T A156171 10298220348807,1396920580458279,270394562069007327, %U A156171 74574294532698008703,29276455806256470979269 %N A156171 G.f.: A(x) = exp( Sum_{n>=1} [x/(1 - 2^n*x)]^n/n ), a power series in x with integer coefficients. %e A156171 G.f.: A(x) = 1 + x + 3*x^2 + 11*x^3 + 53*x^4 + 357*x^5 + 3521*x^6 +... %e A156171 log(A(x)) = x + 5*x^2/2 + 25*x^3/3 + 161*x^4/4 + 1441*x^5/5 + 18305*x^6/ 6 +... %e A156171 Log series: %e A156171 log(A(x)) = Sum_{n>=1} (x + 2^n*x^2 + 4^n*x^3 +...+ 2^(n(k-1))*x^k +...)^n/ n. %o A156171 (PARI) {a(n)=polcoeff(exp(sum(m=1,n,x^m/(1-2^m*x+x*O(x^n))^m/m)),n)} %Y A156171 Cf. A156170, A155200, A156100. %Y A156171 Sequence in context: A000255 A121580 A081367 this_sequence A129093 A057325 A054700 %Y A156171 Adjacent sequences: A156168 A156169 A156170 this_sequence A156172 A156173 A156174 %K A156171 nonn %O A156171 0,3 %A A156171 Paul D. Hanna (pauldhanna(AT)juno.com), Feb 05 2009 Search completed in 0.001 seconds