The (n,r)-th term of the following triangle is T(n)-T(r) for r = 0 to n. The n-th row contains n+1 terms. T(n) = the n-th triangular number = n(n+1)/2. Sequence contains the sum of terms at a 45-degree angle.
A109900
The (n,r)-th term of the following triangle is T(n)-T(r) for r = 0 to n. The n-th row contains n+1 terms. T(n) = the n-th triangular number = n(n+1)/2. Sequence contains the sum of terms at a 45-degree angle.
Terms
- a(0) =0a(1) =1a(2) =3a(3) =8a(4) =15a(5) =27a(6) =42a(7) =64a(8) =90a(9) =125a(10) =165a(11) =216a(12) =273a(13) =343a(14) =420a(15) =512a(16) =612a(17) =729a(18) =855a(19) =1000a(20) =1155a(21) =1331a(22) =1518a(23) =1728a(24) =1950a(25) =2197a(26) =2457a(27) =2744a(28) =3045a(29) =3375
External references
- oeis: A109900