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A117809 a(n,m) =Floor[N[(-2 + Sqrt[3])^n + (-2 - Sqrt[3])^n]/2^m]. 1
-2, 7, 3, -26, -13, -7, 96, 48, 24, 12, -362, -181, -91, -46, -23, 1350, 675, 337, 168, 84, 42, -5042, -2521, -1261, -631, -316, -158, -79, 18816, 9408, 4704, 2352, 1176, 588, 294, 147, -70226, -35113, -17557, -8779, -4390, -2195, -1098, -549, -275, 262086, 131043, 65521, 32760, 16380, 8190, 4095 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

A triangular prime alternating sign Binet like function.

LINKS

Table of n, a(n) for n=0..51.

EXAMPLE

-2

7, 3

-26, -13,-7

96, 48, 24, 12

-362,-181, -91, -46, -23

1350, 675, 337, 168, 84, 42

MATHEMATICA

f[n_, m_] = N[(-2 + Sqrt[3])^n + (-2 - Sqrt[3])^n]/2^m a = Table[Table[Floor[f[n, m]], {m, 1, n}], {n, 1, 10}] aa = Flatten[a] pp = Flatten[Table[If[PrimeQ[aa[[n]]], aa[[n]], {}], {n, 1, Length[aa]}]] Length[pp]/Length[aa]

CROSSREFS

Sequence in context: A089124 A210662 A229610 * A052091 A090276 A249782

Adjacent sequences:  A117806 A117807 A117808 * A117810 A117811 A117812

KEYWORD

sign,tabl

AUTHOR

Roger L. Bagula, Apr 29 2006

STATUS

approved

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Last modified April 25 23:48 EDT 2019. Contains 322465 sequences. (Running on oeis4.)