LINKS
Harvey P. Dale, <a href="/A011864/b011864_1.txt">Table of n, a(n) for n = 0..1000</a>
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Revision History for A011864
(Bold, blue-underlined text is an addition; faded, red-underlined text is aShowing entries 1-10 | older changes
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LINKS
Harvey P. Dale, <a href="/A011864/b011864_1.txt">Table of n, a(n) for n = 0..1000</a>
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MATHEMATICA
Table[Floor[(n(n-1))/11], {n, 0, 70}] (* Harvey P. Dale, Mar 03 2024 *)
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MATHEMATICA
LinearRecurrence[{2, -1, 0, 0, 0, 0, 0, 0, 0, 0, 1, -2, 1}, {0, 0, 0, 0, 1, 1, 2, 3, 5, 6, 8, 10, 12}, 64] (* Peter Luschny, Aug 13 2021 *)
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NAME
[ a(n) = floor(n*(n - 1)/11 ]).
FORMULA
From R. J. Mathar, Apr 15 2010: (Start)
a(n) = 2*a(n - 1) - a(n - 2) + a(n - 11) - 2*a(n - 12) + a(n - 13).
a(n) = +2*a(n-1) -a(n-2) +a(n-11) -2*a(n-12) +a(n-13). G.f.: x^4*(x^2 - x + 1)*(1 + x^4)/ ((1 - x)^3 * (1 + x + x^2 + x^3 + x^4 + x^5 + x^6 + x^7 + x^8 + x^9 + x^10)). [_R. J. Mathar_, Apr 15 2010](End)
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