A129110 A transformation of the Catalan sequence.

1, 2, 1, -1, 1, 6, 1, -13, 1, 43, 1, -131, 1, 430, 1, -1429, 1, 4863, 1, -16795, 1, 58787, 1, -208011, 1, 742901, 1, -2674439, 1, 9694846, 1, -35357669, 1, 129644791, 1, -477638699, 1, 1767263191, 1, -6564120419, 1, 24466267021, 1, -91482563639, 1, 343059613651

Offset: 0

Author

Paul Curtz, May 24 2007

Keywords

• sign

Formula

a(2n)=1. a(2n+1)= 1+(-1)^n*C(n+1), where C=A000108.

a(n+1)-a(n) = A129996(n) (similar to A099363 and A106181).

Extensions

Edited and extended by R. J. Mathar, Jul 04 2008