OFFSET
1,1
COMMENTS
Bombieri's Napkin Problem: Bombieri said that "the equation C(x,n) + C(y,n) = C(z,n) has no trivial solutions for n >= 3" (the joke being that he said "trivial" rather than "nontrivial"!).
Also: tetrahedral numbers that are the sum of two other tetrahedral numbers. (For the indices of these terms, see A002311.) - Harvey P. Dale, Jul 25 2011
REFERENCES
Van der Poorten, Notes on Fermat's Last Theorem, Wiley, p. 122.
LINKS
Delbert L. Johnson, Table of n, a(n) for n = 1..672
FORMULA
EXAMPLE
C(10,3) + C(16,3) = C(17,3) = 680.
MATHEMATICA
With[{tetras=Binomial[Range[700]+2, 3]}, Union[Select[Total/@Tuples[ tetras, 2], MemberQ[tetras, #]&]]] (* Harvey P. Dale, Jul 25 2011 *)
PROG
(Haskell)
a034404 = a000292 . a002311 -- Reinhard Zumkeller, May 02 2014
CROSSREFS
KEYWORD
nonn,nice
AUTHOR
EXTENSIONS
Offset corrected by Andrew Howroyd, Mar 23 2023
STATUS
approved