a(n) = one-half of the number of cells in the central rectangle of the graph described in row 2n+1 of A333288.

A337640

a(n) = one-half of the number of cells in the central rectangle of the graph described in row 2n+1 of A333288.

Terms

    a(0) =2a(1) =11a(2) =35a(3) =80a(4) =155a(5) =266a(6) =422a(7) =626a(8) =890a(9) =1223a(10) =1625a(11) =2108a(12) =2678a(13) =3341a(14) =4109a(15) =4988a(16) =5990a(17) =7106a(18) =8348a(19) =9734a(20) =11264a(21) =12953a(22) =14801a(23) =16820a(24) =19019a(25) =21389a(26) =23957a(27) =26717a(28) =29663a(29) =32834

External references