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A142705
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First bisection of A061037.
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7
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0, 3, 2, 15, 6, 35, 12, 63, 20, 99, 30, 143, 42, 195, 56, 255, 72, 323, 90, 399, 110, 483, 132, 575, 156, 675, 182, 783, 210, 899, 240, 1023, 272, 1155, 306, 1295, 342, 1443, 380, 1599, 420, 1763, 462, 1935, 506, 2115, 552, 2303, 600, 2499, 650, 2703, 702
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| Read modulo 10 (the last digits), a sequence with period length 10 results: 0, 3, 2, 5, 6, 5, 2, 3, 0, 9. Read modulo 9, a sequence with period length 18 results.
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LINKS
| Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Index to sequences with linear recurrences with constant coefficients, signature (0,3,0,-3,0,1).
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FORMULA
| a(n) = A061037(2n). a(n)= A070260(n-1), n>1.
a(n) = 3a(n-2)-3a(n-4)+a(n-6).
a(2^(n-1)) = a(1+A000225(n-1)) = 4^(n-1)-1 = A024036(n-1).
a(n)=-(3/4)*(-1)^n*n-(3/8)*(-1)^n*n^2+(5/8)*n^2+(5/4)*n, with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Sep 29 2008]
G.f.: x^2*(3+2x+6x^2-x^4)/(1-x^2)^3. - R. J. Mathar, Oct 24 2008
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PROG
| (MAGMA) [-(3/4)*(-1)^n*n-(3/8)*(-1)^n*n^2+(5/8)*n^2+(5/4)*n: n in [0..60]]; // Vincenzo Librandi, Jul 02 2011
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CROSSREFS
| Cf. A078371 (second bisection of A061037), A142888 (first differences).
Sequence in context: A068310 A033314 A070260 * A072346 A103236 A141235
Adjacent sequences: A142702 A142703 A142704 * A142706 A142707 A142708
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KEYWORD
| nonn,easy
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AUTHOR
| Paul Curtz (bpcrtz(AT)free.fr), Sep 24 2008
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EXTENSIONS
| Edited by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 24 2008
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