Number of integer compositions of n whose length is twice their alternating sum.

Terms

a(0) =1a(1) =0a(2) =0a(3) =1a(4) =0a(5) =1a(6) =3a(7) =1a(8) =8a(9) =11a(10) =15a(11) =46a(12) =59a(13) =127a(14) =259a(15) =407a(16) =888a(17) =1591a(18) =2925a(19) =5896a(20) =10607a(21) =20582a(22) =39446a(23) =73448a(24) =142691a(25) =269777a(26) =513721a(27) =988638a(28) =1876107a(29) =3600313