Number of atoms in a decahedron with n shells.

Terms

a(0) =0a(1) =1a(2) =7a(3) =23a(4) =54a(5) =105a(6) =181a(7) =287a(8) =428a(9) =609a(10) =835a(11) =1111a(12) =1442a(13) =1833a(14) =2289a(15) =2815a(16) =3416a(17) =4097a(18) =4863a(19) =5719a(20) =6670a(21) =7721a(22) =8877a(23) =10143a(24) =11524a(25) =13025a(26) =14651a(27) =16407a(28) =18298a(29) =20329