A076655 Numerator of a(n), where for n > 2, a(n)=-1/a(n-1)+1/a(n-2), a(1)=1, a(2)=2.

1, 2, 1, -3, 8, -25, 267, -11408, 4063825, -61874069763, 376863853335803168, -33029401504744904404673707225

Offset

1,2

Links

Table of n, a(n) for n=1..12.

Formula

a(n>2)=-1/a(n-1)+1/a(n-2), a(1)=1, a(2)=2, a(n)->-(-1)^n sqrt(2).

Example

a(3)=-1/a(2)+1/a(1)=-1/2+1=1/2, therefore in the sequence, 3rd term is 1.

Crossrefs

Cf. A074935.

Sequence in context: A329180 A302544 A057300 * A236438 A101486 A086606

Adjacent sequences: A076652 A076653 A076654 * A076656 A076657 A076658

Keyword

sign,frac

Author

Zak Seidov, Oct 24 2002

Status

approved