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 A138380 First differences of A138377. 3
 1, 2, -1, -2, -4, -8, 4, 8, 16, 32, -16, -32, -64, -128, 64, 128, 256, 512, -256, -512, -1024, -2048, 1024, 2048, 4096, 8192, -4096, -8192, -16384, -32768, 16384, 32768, 65536, 131072, -65536, -131072, -262144, -524288, 262144, 524288, 1048576, 2097152 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS All terms are powers of 2 (see comment in A138377). - Michel Marcus, Dec 01 2015 LINKS Colin Barker, Table of n, a(n) for n = 0..1000 Index entries for linear recurrences with constant coefficients, signature (0,0,0,-4). FORMULA From Colin Barker, Dec 01 2015: (Start) a(n) = -4*a(n-4) for n>3. G.f.: (1-x)*(1+x)*(1+2*x) / ((1-2*x+2*x^2)*(1+2*x+2*x^2)). (End) MATHEMATICA Differences[LinearRecurrence[{0, 0, 0, -4}, {0, 1, 3, 2}, 60]] (* Harvey P. Dale, Mar 19 2012 *) LinearRecurrence[{0, 0, 0, -4}, {1, 2, -1, -2}, 59] (* Ray Chandler, Aug 03 2015 *) PROG (PARI) Vec((1-x)*(1+x)*(1+2*x)/((1-2*x+2*x^2)*(1+2*x+2*x^2)) + O(x^100)) \\ Colin Barker, Dec 01 2015 CROSSREFS Sequence in context: A279586 A275762 A139248 * A016013 A193384 A049903 Adjacent sequences:  A138377 A138378 A138379 * A138381 A138382 A138383 KEYWORD sign,easy AUTHOR Paul Curtz, May 08 2008 EXTENSIONS More terms from Harvey P. Dale, Mar 19 2012 Missing terms added by Colin Barker, Dec 01 2015 STATUS approved

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Last modified October 23 12:00 EDT 2018. Contains 316527 sequences. (Running on oeis4.)