a(n) = numerator of Sum_{k=1..n} k^mu(n+1-k), where mu(m) = A008683(m).

Terms

a(0) =1a(1) =3a(2) =9a(3) =35a(4) =91a(5) =179a(6) =117a(7) =1181a(8) =14113a(9) =1415a(10) =14839a(11) =35617a(12) =85271a(13) =53251a(14) =3503033a(15) =1879a(16) =12165719a(17) =106753a(18) =2870239a(19) =6436711a(20) =46663061a(21) =402271a(22) =850810423a(23) =60658043a(24) =1473361913a(25) =10236631a(26) =21081760033a(27) =39731443