Number of compositions of n such that the least part occurs with even multiplicity.

Terms

a(0) =0a(1) =1a(2) =0a(3) =5a(4) =3a(5) =16a(6) =23a(7) =64a(8) =102a(9) =251a(10) =464a(11) =999a(12) =1920a(13) =4023a(14) =7910a(15) =16154a(16) =32059a(17) =64894a(18) =129368a(19) =260319a(20) =520057a(21) =1043669a(22) =2086532a(23) =4180928a(24) =8361875a(25) =16741659a(26) =33486337a(27) =67014046a(28) =134043807a(29) =268184694