The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A011868 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A011868

a(n) = floor(n*(n-1)/15).
(history; published version)

#21 by N. J. A. Sloane at Sun Aug 15 05:16:03 EDT 2021

STATUS

proposed

approved

#20 by Michel Marcus at Sun Aug 15 04:47:34 EDT 2021

STATUS

editing

proposed

#19 by Michel Marcus at Sun Aug 15 04:47:29 EDT 2021

MATHEMATICA

LinearRecurrence[{2, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -2, 1}, {0, 0, 0, 0, 0, 1, 2, 2, 3, 4, 6, 7, 8, 10, 12, 14, 16}, 63] (* _Georg Fischer_, Aug 15 2021 *)

0, 0, 0, 0, 1, 2, 2, 3, 4, 6, 7, 8, 10, 12, 14, 16}, 63] (* Georg Fischer, Aug 15 2021 *)

STATUS

proposed

editing

#18 by Georg Fischer at Sun Aug 15 04:12:49 EDT 2021

STATUS

editing

proposed

#17 by Georg Fischer at Sun Aug 15 04:12:26 EDT 2021

MATHEMATICA

0, 0, 0, 0, 1, 2, 2, 3, 4, 6, 7, 8, 10, 12, 14, 16}, 63] (* _Georg Fischer_, Aug 15 2021 *)

STATUS

proposed

editing

Discussion

Sun Aug 15

04:12

Georg Fischer: Ok, thank you.

#16 by Michel Marcus at Sun Aug 15 04:03:24 EDT 2021

STATUS

editing

proposed

#15 by Michel Marcus at Sun Aug 15 04:03:03 EDT 2021

NAME

a(n) = floor(n*(n-1)/15).

FORMULA

From _R. J. Mathar, _, Apr 15 2010: (Start)

G.f.: x^5 *(1+x^2 *(-1+x *(1+x^2 *(1+x *(-1+x^2))))))/(1+x *(-2+x *(1+x^13 *(-1+(2-x) *x)))). (End)

MATHEMATICA

LinearRecurrence[{2, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -2, 1}, {0,

STATUS

proposed

editing

Discussion

Sun Aug 15

04:03

Michel Marcus: I found missing parentheses, ok now ?

#14 by Georg Fischer at Sun Aug 15 03:59:48 EDT 2021

STATUS

editing

proposed

#13 by Georg Fischer at Sun Aug 15 03:59:36 EDT 2021

NAME

[ a(n) = floor(n(n-1)/15 ]).

DATA

0, 0, 0, 0, 0, 1, 2, 2, 3, 4, 6, 7, 8, 10, 12, 14, 16, 18, 20, 22, 25, 28, 30, 33, 36, 40, 43, 46, 50, 54, 58, 62, 66, 70, 74, 79, 84, 88, 93, 98, 104, 109, 114, 120, 126, 132, 138, 144, 150, 156, 163, 170, 176, 183, 190, 198, 205, 212, 220, 228, 236, 244, 252

LINKS

<a href="/index/Rec#order_17">Index entries for linear recurrences with constant coefficients</a>, order 17signature (2,-1,0,0,0,0,0,0,0,0,0,0,0,0,1,-2,1).

FORMULA

From R. J. Mathar, Apr 15 2010: (Start)

a(n) = +2*a(n-1) - a(n-2) + a(n-15) - 2*a(n-16) + a(n-17). [From _R. J. Mathar_, Apr 15 2010]

G.f.: x^5 (1+x^2 (-1+x (1+x^2 (1+x (-1+x^2))))))/(1+x (-2+x (1+x^13 (-1+(2-x) x))). (End)

MATHEMATICA

LinearRecurrence[{2, -1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -2, 1}, {0,

0, 0, 0, 0, 1, 2, 2, 3, 4, 6, 7, 8, 10, 12, 14, 16}, 63] (* Georg Fischer_, Aug 15 2021 *)

KEYWORD

nonn,easy,changed

STATUS

approved

editing

#12 by R. J. Mathar at Wed Aug 11 08:22:13 EDT 2021

STATUS

editing

approved