Number of compositions of n that are anti-palindromic modulo 3.

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =5a(5) =7a(6) =15a(7) =27a(8) =43a(9) =81a(10) =147a(11) =249a(12) =449a(13) =809a(14) =1409a(15) =2507a(16) =4485a(17) =7903a(18) =14015a(19) =24963a(20) =44187a(21) =78329a(22) =139203a(23) =246801a(24) =437601a(25) =776881a(26) =1378081a(27) =2444083a(28) =4337125a(29) =7694487