login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A180591 G.f.: A(x) = exp( Sum_{n>=1} 2^[A001511(n)^2]*x^n/n ) where A001511(n) is the exponent in the highest power of 2 that divides 2n. 1

%I #2 Mar 30 2012 18:37:22

%S 1,2,10,18,178,338,1450,2562,23234,43906,186602,329298,2276914,

%T 4224530,16898506,29572482,191488770,353405058,1394069578,2434734098,

%U 14073489714,25712245330,97969052778,170225860226,938475356354

%N G.f.: A(x) = exp( Sum_{n>=1} 2^[A001511(n)^2]*x^n/n ) where A001511(n) is the exponent in the highest power of 2 that divides 2n.

%e G.f.: A(x) = 1 + 2*x + 10*x^2 + 18*x^3 + 178*x^4 + 338*x^5 +...

%e log(A(x)) = 2^1*x + 2^4*x^2/2 + 2^1*x^3/3 + 2^9*x^4/4 + 2^1*x^5/5 + 2^4*x^6/6 + 2^1*x^7/7 + 2^16*x^8/8 +...+ 2^[A001511(n)^2]*x^n/n +...

%o (PARI) {a(n)=polcoeff(exp(sum(m=1,n,2^(valuation(2*m,2)^2)*x^m/m)+x*O(x^n)),n)}

%Y Cf. A155200, A001511, A000123.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Sep 10 2010

%E Name corrected by _Paul D. Hanna_, Sep 19 2010

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)