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A002613
Glaisher's function J(n) (18 squares version).
(Formerly M5284 N2300)
1
1, 44, 432, -1136, 610, -5568, 6048, 11456, -3423, 26840, -79920, 768, -5470, -77952, 263520, 61696, 73090, -150612, -84240, -692960, -139776, 1030080, -1025568, 1410048, -18525, -240680, 1355616, 10752, -128222, -3396480, -293760
OFFSET
1,2
COMMENTS
It would be nice to have a q-series that generates this sequence. Glaisher gives many formulas but they are difficult to follow.
REFERENCES
J. W. L. Glaisher, On the representation of a number as sum of 18 squares, Quart. J. Math. 38 (1907), 289-351 (see p. 329). [The whole 1907 volume of The Quarterly Journal of Pure and Applied Mathematics, volume 38, is freely available from Google Books]
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
FORMULA
a(n) = -(1/4)*(A002609(2*n) + 16*A002609(n)). - Sean A. Irvine, Mar 04 2019
CROSSREFS
Cf. A002609.
Sequence in context: A231217 A250336 A250337 * A094201 A210426 A231242
KEYWORD
sign
EXTENSIONS
Edited and signs added by N. J. A. Sloane, Nov 26 2018
More terms from Sean A. Irvine, Mar 04 2019
STATUS
approved