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 A110148 Number of perfect squared rectangles of order n up to symmetries of the rectangle and of its subrectangles if any. 5
 0, 0, 0, 0, 0, 0, 0, 0, 2, 10, 38, 127, 408, 1375, 4783, 16645, 58059, 203808, 722575 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,9 COMMENTS A squared rectangle (which may be a square) is a rectangle dissected into a finite number, two or more, of squares. If no two of these squares have the same size the squared rectangle is perfect. The order of a squared rectangle is the number of constituent squares. [Geoffrey H. Morley, Oct 12 2012] LINKS C. J. Bouwkamp, On the dissection of rectangles into squares (Papers I-III), Koninklijke Nederlandsche Akademie van Wetenschappen, Proc., Ser. A, Paper I, 49 (1946), 1176-1188 (=Indagationes Math., v. 8 (1946), 724-736); Paper II, 50 (1947), 58-71 (=Indagationes Math., v. 9 (1947), 43-56); Paper III, 50 (1947), 72-78 (=Indagationes Math., v. 9 (1947), 57-63). [Paper I has terms up to a(12) and an incorrect value for a(13) on p. 1178.] C. J. Bouwkamp, On the construction of simple perfect squared squares, Koninklijke Nederlandsche Akademie van Wetenschappen, Proc., Ser. A, 50 (1947), 1296-1299 (=Indagationes Math., v. 9 (1947), 622-625). [Correct terms up to a(13) on p. 1299.] I. M. Yaglom, How to dissect a square? (in Russian), Nauka, Moscow, 1968. In djvu format (1.7M), also as this pdf (9.5M). [Terms up to a(13) on pp. 26-7.] FORMULA a(n) = A002839(n) + A217152(n) + A217374(n). - Geoffrey H. Morley, Oct 12 2012 a(n) = a(n-1) + A002839(n) + A002839(n-1) + A217152(n) + A217152(n-1). - Geoffrey H. Morley, Oct 12 2012 CROSSREFS Cf. A217154 (counts symmetries of any subrectangles as distinct). Cf. A181735, A217153, A217156. Sequence in context: A046241 A048499 A119358 * A281199 A056182 A081956 Adjacent sequences:  A110145 A110146 A110147 * A110149 A110150 A110151 KEYWORD nonn,hard,more AUTHOR Tanya Khovanova, Feb 18 2007 EXTENSIONS Definition corrected and a(14)-a(19) added by Geoffrey H. Morley, Oct 12 2012 STATUS approved

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Last modified December 16 01:14 EST 2018. Contains 318158 sequences. (Running on oeis4.)