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A126719 -n^2 + 9n + 23. 6
23, 31, 37, 41, 43, 43, 41, 37, 31, 23, 13, 1, -13, -29, -47, -67, -89, -113, -139, -167, -197, -229, -263, -299, -337, -377, -419, -463, -509, -557, -607, -659, -713, -769, -827, -887, -949, -1013, -1079, -1147, -1217, -1289, -1363, -1439, -1517, -1597, -1679, -1763, -1849, -1937, -2027, -2119, -2213 (list; graph; refs; listen; history; internal format)
OFFSET

0,1

COMMENTS

Derivation is similar to that of A126665, which see for further information.

LINKS

Michael M. Ross, Natural Numbers

Robert Sacks Number Spiral: Method of Common Differences.

Harvey P. Dale, Table of n, a(n) for n = 0..1000

FORMULA

a(0)=23, a(1)=31, a(2)=37, a(n)=3*a(n-1)-3*a(n-2)+a(n-3) [From Harvey P. Dale, Oct 19 2011]

G.f.: ((38-13*x)*x-23)/(x-1)^3 [From Harvey P. Dale, Oct 19 2011]

EXAMPLE

-1*8^2 + 9*8 + 23 = 31

MATHEMATICA

Table[-n^2+9n+23, {n, 0, 60}] (* or *) LinearRecurrence[{3, -3, 1}, {23, 31, 37}, 60] (* From Harvey P. Dale, Oct 19 2011 *)

PROG

QTest: Quadratic equation derivation and prime number generation. Vortex: View and analyze the Sacks Number Spiral.

CROSSREFS

Sequence in context: A036267 A107934 A155107 * A110677 A169640 A026051

Adjacent sequences:  A126716 A126717 A126718 * A126720 A126721 A126722

KEYWORD

sign

AUTHOR

Michael M. Ross (michaelmross(AT)comcast.net), Mar 13 2007

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Last modified February 15 12:25 EST 2012. Contains 205786 sequences.