A001014 Sixth powers: a(n) = n^6. (Formerly M5330 N2318)

0, 1, 64, 729, 4096, 15625, 46656, 117649, 262144, 531441, 1000000, 1771561, 2985984, 4826809, 7529536, 11390625, 16777216, 24137569, 34012224, 47045881, 64000000, 85766121, 113379904, 148035889, 191102976, 244140625, 308915776, 387420489, 481890304

Offset

0,3

Comments

Numbers both square and cubic. - Patrick De Geest

Totally multiplicative sequence with a(p) = p^6 for prime p. - Jaroslav Krizek, Nov 01 2009

Numbers n for which order of torsion subgroup t of the elliptic curve y^2=x^3+n is t=6. - Artur Jasinski, Jun 30 2010

Besides the first term, this sequence is the denominator of ((Pi)^6)/945 = 1 + 1/64 + 1/729 + 1/4096 + 1/15625 + 1/46656 + ... - Mohammad K. Azarian, Nov 01 2011

The binomial transform yields A056468. The inverse binomial transform yields the (finite) 0, 1, 62, 540, ..., 720, the 6th row in A019538 and A131689. - R. J. Mathar, Jan 16 2013

For n > 0, a(n) is the largest number k such that k + n^3 divides k^2 + n^3. - Derek Orr, Oct 01 2014

References

R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. Addison-Wesley, Reading, MA, 1990, p. 255; 2nd. ed., p. 269. Worpitzky's identity, eq. (6.37).

Granino A. Korn and Theresa M.Korn, Mathematical Handbook for Scientists and Engineers, McGraw-Hill Book Company, New York (1968), p. 982.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Franklin T. Adams-Watters, Table of n, a(n) for n = 0..500

Henry Bottomley, Illustration of initial terms

J. Gebel, Integer points on Mordell curves [Cached copy, after the original web site tnt.math.se.tmu.ac.jp was shut down in 2017]

Richard J. Mathar, Construction of Bhaskara pairs, arXiv:1703.01677 [math.NT], 2017.

Simon Plouffe, Approximations de séries génératrices et quelques conjectures, Dissertation, Université du Québec à Montréal, 1992; arXiv:0911.4975 [math.NT], 2009.

Simon Plouffe, 1031 Generating Functions, Appendix to Thesis, Montreal, 1992

Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).

Formula

a(n) = A123866(n) + 1 = A002604(n) - 1.

G.f.: -x*(1+x)*(x^4+56*x^3+246*x^2+56*x+1) / (x-1)^7. - Simon Plouffe in his 1992 dissertation

Multiplicative with a(p^e) = p^(6e). - David W. Wilson, Aug 01 2001

E.g.f.: (x + 31x^2 + 90x^3 + 65x^4 + 15x^5 + x^6)*exp(x). Generally, the e.g.f. for n^m is Sum_{k=1..m} A008277(m,k)*x^k*exp(x). - Geoffrey Critzer, Aug 25 2013

From Ant King, Sep 23 2013: (Start)

Signature {7, -21, 35, -35, 21, -7, 1}.

a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) + 720. (End)

a(n) == 1 (mod 7) if gcd(n, 7) = 1, otherwise a(n) == 0 (mod 7). See A109720. - Jake Lawrence, May 28 2016

From Ilya Gutkovskiy, Jul 06 2016: (Start)

Dirichlet g.f.: zeta(s-6).

Sum_{n>=1} 1/a(n) = Pi^6/945 = A013664. (End)

a(n) = Sum_{k=1..6} Eulerian(6, k)*binomial(n+6-k, 6), with Eulerian(6, k) = A008292(6, k) (the numbers are 1, 57, 302, 302, 57, 1) for n >= 0. Worpitzki's identity for powers of 6. See. e.g., Graham et al., eq. (6, 37) (using A173018, the row reversed version of A123125). - Wolfdieter Lang, Jul 17 2019

Sum_{n>=1} (-1)^(n+1)/a(n) = 31*zeta(6)/32 = 31*Pi^6/30240 (A275703). - Amiram Eldar, Oct 08 2020

From Amiram Eldar, Jan 20 2021: (Start)

Product_{n>=1} (1 + 1/a(n)) = (cosh(Pi)-cos(sqrt(3)*Pi))*sinh(Pi)/(2*Pi^3).

Product_{n>=2} (1 - 1/a(n)) = cosh(sqrt(3)*Pi/2)^2/(6*Pi^2). (End)

Mathematica

Table[n^6, {n, 0, 40}] (* Vladimir Joseph Stephan Orlovsky, Feb 19 2010 *)

Prog

(Haskell)
a001014 n = a001014_list !! n
a001014_list = map (^ 6) [0..] -- Reinhard Zumkeller, Dec 04 2011
(Maxima) A001014(n):=n^6$
makelist(A001014(n), n, 0, 30); /* Martin Ettl, Nov 05 2012 */
(PARI) a(n)=n^6 \\ Charles R Greathouse IV, Sep 24 2015

Crossrefs

Subsequence of A201217.

Cf. A000540 (partial sums), A022522 (first differences), A008292.

Intersection of A000290 and A000578.

Cf. A002604, A013664, A123866, A275703.

Sequence in context: A346638 A017676 A055015 * A352052 A050753 A074154

Adjacent sequences: A001011 A001012 A001013 * A001015 A001016 A001017

Keyword

nonn,easy,mult

Author

N. J. A. Sloane

Status

approved