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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A064556 Ramanujan's tau function (or tau numbers (A000594)) for 10^n. 3
1, -115920, 37534859200, -30328412970240000, -482606811957501440000, -2983637890141033828147200000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..181

MATHEMATICA

Table[ RamanujanTau[10^n], {n, 0, 5}]

PROG

(Perl) use bigint; use ntheory ":all"; say "$_ ", ramanujan_tau(10 ** $_) for 0..19; # Dana Jacobsen, Sep 05 2015

(PARI) taup(p, e)={

    if(e==1,

        (65*sigma(p, 11)+691*sigma(p, 5)-691*252*sum(k=1, p-1, sigma(k, 5)*sigma(p-k, 5)))/756

    ,

        my(t=taup(p, 1));

        sum(j=0, e\2,

            (-1)^j*binomial(e-j, e-2*j)*p^(11*j)*t^(e-2*j)

        )

    )

};

a(n)=taup(5, n)*taup(2, n) \\ Charles R Greathouse IV, Sep 06 2015

CROSSREFS

Cf. A000594, A035174.

Sequence in context: A237382 A255080 A232577 * A255950 A273660 A254565

Adjacent sequences:  A064553 A064554 A064555 * A064557 A064558 A064559

KEYWORD

sign

AUTHOR

Robert G. Wilson v, Jan 04 2003

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.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 26 03:14 EDT 2020. Contains 337346 sequences. (Running on oeis4.)