Trisection A061037(3*n-2) of the Balmer spectrum numerators extended to negative indices.

Terms

a(0) =0a(1) =-3a(2) =3a(3) =45a(4) =6a(5) =165a(6) =63a(7) =357a(8) =30a(9) =621a(10) =195a(11) =957a(12) =72a(13) =1365a(14) =399a(15) =1845a(16) =132a(17) =2397a(18) =675a(19) =3021a(20) =210a(21) =3717a(22) =1023a(23) =4485a(24) =306a(25) =5325a(26) =1443a(27) =6237a(28) =420a(29) =7221