1,1

R. K. Guy, Unsolved Problems in Number Theory, Section D1.

G. H. Hardy, Ramanujan, Cambridge Univ. Press, 1940, p. 12.

J. Leech, Some solutions of Diophantine equations, Proc. Camb. Phil. Soc., 53 (1957), 778-780, see p. 799.

Ya. I. Perelman, Algebra can be fun, pp. 142-143.

H. W. Richmond, On integers which satisfy ..., Trans. Camb. Phil. Soc., 22 (1920), 389-403, see p. 402.

D. Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, 165.

T. D. Noe, Table of n, a(n) for n=1..4724

Anonymous, Srinivasa Ramanujan

J. Charles-E [is that name correct?], Recreomath, Ramanujan's Number

A. Grinstein, Ramanujan and 1729

Istambul Bilgi University, Ramanujan and Hardy's Taxi

Christopher Lane, The First ten Ta(2) and their double distinct cubic sums representations, Find Ramanujan's Taxi Number using JavaScript

J. Loy, The Hardy-Ramanujan Number

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics (1).

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics (2).

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics (3).

D. W. Wilson, The Fifth Taxicab Number is 48988659276962496, J. Integer Sequences, Vol. 2, 1999, #99.1.9.

4104 belongs to the sequence as 4104 = 2^3 + 16^3 = 9^3 + 15^3.

lst={}; q=-1; k=1; Do[Do[x=a^3; Do[y=b^3; If[x+y==n, If[n==q&&k==1, AppendTo[lst, n]]; If[n!=q, q=n; k=1, k++ ]], {b, Floor[(n-x)^(1/3)], a+1, -1}], {a, Floor[n^(1/3)], 1, -1}], {n, 2*6!, 8!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jan 22 2009]

Cf. A018850, A011541, A003826, A023050, A023051.

Sequence in context: A154729 A083737 A138129 this_sequence A018850 A062924 A130859

Adjacent sequences: A001232 A001233 A001234 this_sequence A001236 A001237 A001238

nonn,nice

N. J. A. Sloane (njas(AT)research.att.com).