login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Expansion of j in powers of Gamma(5)-modular function Lambda^5.
2

%I #5 Apr 30 2014 01:38:50

%S 1,739,196874,22478125,1086128125,35307387500,913727546875,

%T 20389341653125,410010534950000,7633186177665625,133911227595521875,

%U 2240979684247156250,36090410657726350000,563019001047724506250

%N Expansion of j in powers of Gamma(5)-modular function Lambda^5.

%D W. Duke, Continued fractions and modular functions, Bull. Amer. Math. Soc., 42 (2005), 137-162; see Eq. (5.3).

%D A. Erdelyi, Higher Transcendental Functions, McGraw-Hill, 1955, Vol. 3, p. 24.

%D H. McKean and V. Moll. Elliptic Curves, Camb. Univ. Press, p. 22.

%F G.f.: (1+228x+494x^2-228x^3+x^4)^3/(x(1-11x-x^2)^5).

%e j = 1/x + 739 + 196874*x + 22478125*x^2 + ... where x=Lambda^5=A078905.

%p t1:=1+228*z+494*z^2-228*z^3+z^4; t2:=-t1^3/(z*(z^2+11*z-1)^5); # t2 is Duke's g.f.

%o (PARI) a(n)=polcoeff((1-228*(x^3-x)+494*x^2+x^4)^3/x/(1-11*x-x^2)^5+x*O(x^n),n)

%Y Cf. A078905, A000521. A066404(n)=(-1)^n*a(n-1).

%K nonn,easy

%O -1,2

%A _Michael Somos_, Dec 12 2002