The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A143557 G.f. satisfies: A(x) = 1 + x*A(x)^4/A(-x)^4. 5
 1, 1, 8, 32, 280, 1728, 16744, 117856, 1202552, 9044352, 95203784, 745451168, 8011827928, 64459117632, 703166465320, 5769038826208, 63639465830712, 529889242505984, 5896324892061576, 49665617425122592, 556508207889107096 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS FORMULA G.f. satisfies: A(x) = 1 + x^2/(1 - A(-x)). G.f. satisfies: A(x) = 1 + x^2 + x*A(x)^4 / A(-x)^3. G.f. satisfies: (A(x) - 1)^3 = ( 1 - (1+x^2)/A(x) )^4/x = x^3*A(x)^12/A(-x)^12. G.f.: A(x) = (1+x^2)*G(x) where G(x) = 1 + x*G(x)^4/G(-x)^3 is the g.f. of A143564. EXAMPLE G.f. A(x) = 1 + x + 8*x^2 + 32*x^3 + 280*x^4 + 1728*x^5 + 16744*x^6 +... A(x)/A(-x) = 1 + 2*x + 2*x^2 + 50*x^3 + 98*x^4 + 2658*x^5 + 6370*x^6 +... A(x)^3/A(-x)^3 = 1 + 6*x + 18*x^2 + 182*x^3 + 930*x^4 + 10374*x^5 +... where 1 - (1+x^2)/A(x) = x*A(x)^3/A(-x)^3. PROG (PARI) {a(n)=local(A=1+x*O(x^n)); for(i=0, n, A=1+x*A^4/subst(A^4, x, -x)); polcoeff(A, n)} CROSSREFS Cf. A143564, A143555, A143556, A143558, A143559. Sequence in context: A268143 A093759 A066415 * A208824 A034193 A159277 Adjacent sequences:  A143554 A143555 A143556 * A143558 A143559 A143560 KEYWORD nonn AUTHOR Paul D. Hanna, Aug 24 2008 STATUS approved

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

Last modified September 22 22:24 EDT 2020. Contains 337291 sequences. (Running on oeis4.)