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!)
A333972 Decimal expansion of Pi^6/540 = zeta(2) * zeta(4). 2
1, 7, 8, 0, 3, 5, 0, 3, 5, 8, 4, 7, 2, 7, 8, 5, 9, 9, 4, 5, 0, 0, 4, 0, 6, 3, 7, 7, 1, 3, 4, 1, 1, 0, 9, 2, 3, 8, 2, 8, 1, 8, 0, 6, 0, 7, 5, 5, 7, 4, 9, 3, 7, 3, 3, 2, 2, 4, 2, 1, 5, 1, 6, 2, 0, 0, 7, 5, 8, 1, 3, 2, 0, 0, 7, 8, 4, 2, 6, 3, 2, 1, 2, 9, 4, 8, 5, 4, 4, 6, 1, 3, 9, 2, 4 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Compare 1st formula with Sum_{m>0, q>0} 1/(m^2*q^2) = Pi^4/36 = (zeta(2))^2 = A098198.

REFERENCES

Jean-Marie Monier, Analyse, Exercices corrigés, 2ème année MP, Dunod, 1997, Exercice 3.22, p. 275.

LINKS

Table of n, a(n) for n=1..95.

FORMULA

Equals Sum_{m>0, q>0, m | q} 1/(m^2*q^2).

Equals A013661 * A068447.

Equals Sum_{k>=1} sigma_2(k)/k^4. - Amiram Eldar, Sep 30 2020

EXAMPLE

1.78035035847278599450040637713411092382818060755749373322421516...

MAPLE

evalf(Pi^6/540, 120);

MATHEMATICA

RealDigits[Pi^6/540, 10, 100][[1]] (* Amiram Eldar, Sep 29 2020 *)

PROG

(PARI) Pi^6/540 \\ Michel Marcus, Sep 30 2020

CROSSREFS

Cf. A001157, A013661, A068447, A098198.

Sequence in context: A332634 A330652 A181438 * A088396 A199723 A188485

Adjacent sequences:  A333969 A333970 A333971 * A333973 A333974 A333975

KEYWORD

nonn,cons

AUTHOR

Bernard Schott, Sep 29 2020

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 20 16:50 EDT 2021. Contains 347586 sequences. (Running on oeis4.)