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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A226458 G.f.: exp( Sum_{n>=1} A226459(n)*x^n/n ), where A226459(n) = Sum_{d|n} phi(d^d). 2
 1, 1, 2, 8, 41, 547, 3193, 104733, 1159483, 29990445, 431859113, 24050995053, 272382000003, 21806033497537, 362394321610042, 15956110448082190, 592910703485329797, 46410258555248498805, 775743319456458483203, 99472768731785230089041 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..19. FORMULA The logarithmic derivative yields A226459. EXAMPLE G.f.: A(x) = 1 + x + 2*x^2 + 8*x^3 + 41*x^4 + 547*x^5 + 3193*x^6 +... where log(A(x)) = x + 3*x^2/2 + 19*x^3/3 + 131*x^4/4 + 2501*x^5/5 +...+ A226459(n)*x^n/n +... PROG (PARI) {A226459(n)=sumdiv(n, d, eulerphi(d^d))} {a(n)=polcoeff(exp(sum(m=1, n+1, A226459(m)*x^m/m)+x*O(x^n)), n)} for(n=0, 30, print1(a(n), ", ")) CROSSREFS Cf. A226459, A226560. Sequence in context: A125698 A231495 A052447 * A364383 A330870 A364707 Adjacent sequences: A226455 A226456 A226457 * A226459 A226460 A226461 KEYWORD nonn AUTHOR Paul D. Hanna, Jun 08 2013 STATUS approved

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.

Last modified February 23 21:40 EST 2024. Contains 370288 sequences. (Running on oeis4.)