2nd elementary symmetric function of the first n+1 positive integers congruent to 2 mod 3.

Terms

a(0) =10a(1) =66a(2) =231a(3) =595a(4) =1275a(5) =2415a(6) =4186a(7) =6786a(8) =10440a(9) =15400a(10) =21945a(11) =30381a(12) =41041a(13) =54285a(14) =70500a(15) =90100a(16) =113526a(17) =141246a(18) =173755a(19) =211575a(20) =255255a(21) =305371a(22) =362526a(23) =427350a(24) =500500a(25) =582660a(26) =674541a(27) =776881a(28) =890445a(29) =1016025