0,2

If n != 1 and n^2+2 is prime then n is a member of this sequence. - Cino Hilliard (hillcino368(AT)hotmail.com), Mar 19 2007

Multiples of 3. Positive members of this sequence are the third transversal numbers (or 3-transversal numbers): Numbers of the 3rd column of positive numbers in the square array of nonnegative and polygonal numbers A139600. Also, numbers of the 3rd column in the square array A057145. - Omar E. Pol (info(AT)polprimos.com), May 02 2008

Numbers n for which polynomial 27*x^6-2^n is factorizable. [From Artur Jasinski (grafix(AT)csl.pl), Nov 01 2008]

Also n=0 mod (3); for n>0 first column [A144562] [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Jan 13 2009]

1/7 in base 2 notation = .001001001,...= 1/2^3 + 1/2^6 + 1/2^9 + ... [From Gary W. Adamson (qntmpkt(AT)yahoo.com), Jan 24 2009]

Number of n permutations (n>=1) of 4 objects u, v, z, x, with repetition allowed, containing n-1 u's. Example: if n=1 then n-1=zero (0) u, a(1)=3 because we have v, z, x. if n=2 then n-1= one (1) u, a(2)=6 because we have vu, zu, xu, uv, uz, ux. if n=3 then n-1 =two (2) u, a(3)=9 because we have vuu, uvu, uuv, zuu, uzu, uuz, xuu, uxu, uux, etc. [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 17 2009]

A165330(a(n)) = 153 for n > 0; subsequence of A165332. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Sep 17 2009]

Index entries for sequences related to linear recurrences with constant coefficients

A. S. Fraenkel, New games related to old and new sequences, INTEGERS, Electronic J. of Combinatorial Number Theory, Vol. 4, Paper G6, 2004.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 315

Tanya Khovanova, Recursive Sequences

G.f.: 3x/(1-x)^2. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 23 2008]

a(n)=A008486(n), n>0. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 28 2008]

a(n)=6*n-a(n-1)-9 (with a(1)=0) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 23 2009]

For n=2, a(2)=6*2-0-9=3; n=3, a(3)=6*3-3-9=6; n=4, a(4)=6*4-6-9=9 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Nov 23 2009]

aa = {}; Do[If[Length[FactorList[27 x^6 - 2^n]] > 2, AppendTo[aa, n]], {n, 1, 100}]; aa [From Artur Jasinski (grafix(AT)csl.pl), Nov 01 2008]

Table[Binomial[n, 1]*3^1, {n, 0, 48}] [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 17 2009]

(Other) sage:[i for i in range(145) if gcd(3, i) == 3] [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 21 2009]

Cf. A016957, A057145, A139600, A139606.

Cf. A144562, A067076, A153238 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Jan 13 2009]

A165340. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Sep 17 2009]

Sequence in context: A160943 A160930 A161351 this_sequence A031193 A008486 A135943

Adjacent sequences: A008582 A008583 A008584 this_sequence A008586 A008587 A008588

nonn,new

N. J. A. Sloane (njas(AT)research.att.com).