A014795 Squares of odd tetrahedral numbers.
1, 1225, 27225, 207025, 938961, 3136441, 8555625, 20205025, 42837025, 83521321, 152300281, 262926225, 433680625, 688275225, 1056835081, 1576963521, 2294889025, 3266694025, 4559625625, 6253488241, 8442118161, 11234940025, 14758605225, 19158712225, 24601608801
Offset: 0
Links
- Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
Programs
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Mathematica
Table[((4*n+1)*(4*n+2)*(4*n+3)/6)^2, {n, 0, 40}] (* Amiram Eldar, Mar 07 2022 *)
Formula
From Amiram Eldar, Mar 07 2022: (Start)
a(n) = A015219(n)^2 = ((4*n+1)*(4*n+2)*(4*n+3)/6)^2.
Sum_{n>=0} 1/a(n) = 9*Pi*(Pi-3)/4. (End)
Extensions
More terms from Erich Friedman
More terms from Amiram Eldar, Mar 07 2022