a(n) = T(n) concatenated with reverse(T(n)) divided by 11, where T(n) is the n-th triangular number.

A084008

a(n) = T(n) concatenated with reverse(T(n)) divided by 11, where T(n) is the n-th triangular number.

Terms

    a(0) =0a(1) =1a(2) =3a(3) =6a(4) =91a(5) =141a(6) =192a(7) =262a(8) =333a(9) =414a(10) =505a(11) =606a(12) =717a(13) =829a(14) =9591a(15) =10911a(16) =12421a(17) =13941a(18) =15561a(19) =17281a(20) =19092a(21) =21012a(22) =23032a(23) =25152a(24) =27273a(25) =29593a(26) =31923a(27) =34443a(28) =36964a(29) =39594

External references