Number of compositions of n into powers of 3 and doubled powers of 3.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =7a(5) =13a(6) =25a(7) =46a(8) =86a(9) =162a(10) =302a(11) =565a(12) =1058a(13) =1978a(14) =3700a(15) =6923a(16) =12949a(17) =24223a(18) =45316a(19) =84769a(20) =158575a(21) =296645a(22) =554923a(23) =1038079a(24) =1941911a(25) =3632677a(26) =6795551a(27) =12712263a(28) =23780486a(29) =44485521