Reduced Clausen numbers.

Terms

a(0) =10a(1) =546a(2) =2a(3) =46a(4) =6630a(5) =76670a(6) =211659630a(7) =6a(8) =261870a(9) =111418a(10) =46a(11) =13589784390a(12) =524588442a(13) =114a(15) =2a(16) =276742830a(17) =26805565070a(19) =3210a(20) =15370a(22) =358a(24) =76004922a(25) =1126a(27) =81366