login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A203148 (n-1)-st elementary symmetric function of {3,9,...,3^n}. 4
1, 12, 351, 29160, 7144929, 5223002148, 11433166050879, 75035879252272080, 1477081305957768349761, 87223128348206814118735932, 15451489966710801620870785316511, 8211586182553137756809552940033725880, 13091937140529934508508023103481190655434529 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
From R. J. Mathar, Oct 01 2016: (Start)
The k-th elementary symmetric functions of the integers 3^j, j=1..n, form a triangle T(n,k), 0<=k<=n, n>=0:
1;
1 3;
1 12 27;
1 39 351 729;
1 120 3510 29160 59049;
1 363 32670 882090 7144929 14348907;
which is the row-reversed version of A173007. This here is the first subdiagonal. The diagonal seems to be A047656. The first column is A029858. (End)
LINKS
FORMULA
a(n) = (1/2)*(3^n-1)*3^(binomial(n,2)). - Emanuele Munarini, Sep 14 2017
MATHEMATICA
f[k_]:= 3^k; t[n_]:= Table[f[k], {k, 1, n}];
a[n_]:= SymmetricPolynomial[n - 1, t[n]];
Table[a[n], {n, 1, 16}] (* A203148 *)
Table[1/2 (3^n - 1) 3^Binomial[n, 2], {n, 1, 20}] (* Emanuele Munarini, Sep 14 2017 *)
PROG
(Sage) [(1/2)*(3^n -1)*3^(binomial(n, 2)) for n in (1..20)] # G. C. Greubel, Feb 24 2021
(Magma) [(1/2)*(3^n -1)*3^(Binomial(n, 2)): n in [1..20]]; // G. C. Greubel, Feb 24 2021
CROSSREFS
Cf. A203149.
Sequence in context: A209425 A171206 A219407 * A120813 A202926 A134800
KEYWORD
nonn
AUTHOR
Clark Kimberling, Dec 29 2011
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 21 09:38 EDT 2024. Contains 374472 sequences. (Running on oeis4.)