A180878 Numerator in fraction A180878/A060818.

1, 0, -1, -1, -9, -5, -21, -21, -197, -117, -427, -427, -2501, -1797, -2909, -2909, -72877, -65453

Offset

1,5

Comments

The generating function 1/sqrt((1/x-1)*(1/x+1)) is symmetrical around the origin and has singularities at -1 and +1.

Links

Table of n, a(n) for n=1..18.

Formula

Lambert series: Sum_{n >= 1} A180878(n)/A060818(n)*(x^n/(1-x^n)-x^(n+1)/(1-x^(n+1)))=1/sqrt((1/x-1)*(1/x+1)).

Crossrefs

Cf. Analogous to fraction A180403/A046161.

Sequence in context: A103168 A298584 A238475 * A146282 A117911 A061041

Adjacent sequences: A180875 A180876 A180877 * A180879 A180880 A180881

Keyword

sign

Author

Mats Granvik, Sep 23 2010

Status

approved