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A164006 Zero together with row 6 of the array in A163280. 5
0, 11, 22, 27, 44, 50, 66, 84, 104, 126, 150, 176, 204, 234, 266, 300, 336, 374, 414, 456, 500, 546, 594, 644, 696, 750, 806, 864, 924, 986, 1050, 1116, 1184, 1254, 1326, 1400, 1476, 1554, 1634, 1716, 1800, 1886, 1974, 2064, 2156, 2250, 2346, 2444, 2544, 2646 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

FORMULA

From Colin Barker, Nov 24 2014: (Start)

a(n) = n*(n+5) for n > 4.

a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 7.

G.f.: x*(8*x^6 - 21*x^5 + 23*x^4 - 18*x^3 + 6*x^2 + 11*x - 11) / (x-1)^3. (End)

E.g.f.: (x/2)*(10 + 8*x + x^2 + 2*(x + 6)*exp(x)). - G. C. Greubel, Aug 28 2017

MAPLE

A033676 := proc(n) local a, d; a := 0 ; for d in numtheory[divisors](n) do if d^2 <= n then a := max(a, d) ; fi; od: a; end: A163280 := proc(n, k) local r, T ; r := 0 ; for T from k^2 by k do if A033676(T) = k then r := r+1 ; if r = n then RETURN(T) ; fi; fi; od: end: A164006 := proc(n) if n = 0 then 0; else A163280(6, n) ; fi; end: seq(A164006(n), n=0..80) ; # R. J. Mathar, Aug 09 2009

MATHEMATICA

Join[{0, 11, 22, 27}, Table[n*(n + 5), {n, 4, 50}]] (* G. C. Greubel, Aug 28 2017 *)

PROG

(PARI) concat(0, Vec(x*(8*x^6-21*x^5+23*x^4-18*x^3+6*x^2+11*x-11)/(x-1)^3 + O(x^100))) \\ Colin Barker, Nov 24 2014

CROSSREFS

Cf. A008578, A161344, A161345, A163280, A164000, A164005, A164007.

Cf. A028557 for n > 4. - R. J. Mathar, Aug 09 2009

Sequence in context: A234314 A258738 A160272 * A178736 A054728 A178897

Adjacent sequences:  A164003 A164004 A164005 * A164007 A164008 A164009

KEYWORD

nonn,easy

AUTHOR

Omar E. Pol, Aug 08 2009

EXTENSIONS

Extended beyond a(12) by R. J. Mathar, Aug 09 2009

STATUS

approved

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Last modified October 18 13:31 EDT 2019. Contains 328161 sequences. (Running on oeis4.)