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 A046895 Sizes of successive clusters in Z^4 lattice. 6
 1, 9, 33, 65, 89, 137, 233, 297, 321, 425, 569, 665, 761, 873, 1065, 1257, 1281, 1425, 1737, 1897, 2041, 2297, 2585, 2777, 2873, 3121, 3457, 3777, 3969, 4209, 4785, 5041, 5065, 5449, 5881, 6265, 6577, 6881, 7361, 7809, 7953, 8289, 9057 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Number of lattice points inside or on the 4-sphere x^2+y^2+z^2+u^2=n. - T. D. Noe, Mar 14 2009 LINKS T. D. Noe, Table of n, a(n) for n = 0..1000 FORMULA a(n) = A122510(4,n). a(n^2)=A055410(n). [R. J. Mathar, Apr 21 2010] G.f.: T3(q)^4/(1-q) where T3(q) = 1 + 2*sum(k>=1, q^(k^2) ). [Joerg Arndt, Apr 08 2013] MATHEMATICA Accumulate[ Table[ SquaresR[4, n], {n, 0, 42}]](* Jean-François Alcover, May 11 2012 *) PROG (PARI) q='q+O('q^66); Vec((eta(q^2)^5/(eta(q)^2*eta(q^4)^2))^4/(1-q)) /* Joerg Arndt, Apr 08 2013 */ CROSSREFS Partial sums of A000118. Cf. A117609 Sequence in context: A146262 A161430 A175369 * A165392 A145923 A092562 Adjacent sequences:  A046892 A046893 A046894 * A046896 A046897 A046898 KEYWORD nonn,easy,nice AUTHOR STATUS approved

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Last modified June 20 06:36 EDT 2013. Contains 226422 sequences.