a(n) = Sum_(i=1..n) binomial(i+2,3)^2 [ Sequential sums of the tetragonal numbers or "tetras" (pyramidal, square) raised to power 2 (drawn from the 4th diagonal - left or right - of Pascal's Triangle) ].
A086020
a(n) = Sum_(i=1..n) binomial(i+2,3)^2 [ Sequential sums of the tetragonal numbers or "tetras" (pyramidal, square) raised to power 2 (drawn from the 4th diagonal - left or right - of Pascal's Triangle) ].
Terms
- a(0) =1a(1) =17a(2) =117a(3) =517a(4) =1742a(5) =4878a(6) =11934a(7) =26334a(8) =53559a(9) =101959a(10) =183755a(11) =316251a(12) =523276a(13) =836876a(14) =1299276a(15) =1965132a(16) =2904093a(17) =4203693a(18) =5972593a(19) =8344193a(20) =11480634a(21) =15577210a(22) =20867210a(23) =27627210a(24) =36182835a(25) =46915011a(26) =60266727a(27) =76750327
External references
- oeis: A086020