The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
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!)
A114003 Rows sums of triangle A114002. 8
1, 3, 3, 5, 3, 7, 3, 7, 5, 7, 3, 11, 3, 7, 7, 9, 3, 11, 3, 11, 7, 7, 3, 15, 5, 7, 7, 11, 3, 15, 3, 11, 7, 7, 7, 17, 3, 7, 7, 15, 3, 15, 3, 11, 11, 7, 3, 19, 5, 11, 7, 11, 3, 15, 7, 15, 7, 7, 3, 23, 3, 7, 11, 13, 7, 15, 3, 11, 7, 15, 3, 23, 3, 7, 11, 11, 7, 15, 3, 19, 9, 7, 3, 23, 7, 7, 7, 15, 3, 23, 7, 11, 7, 7, 7, 23, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
FORMULA
a(p) = 3, for primes p.
a(n) = 2*A000005(n) - 1. - Vladeta Jovovic, Sep 13 2006
Equals A051731 * [1, 2, 2, 2, ...]. - Gary W. Adamson, Sep 21 2007
G.f.: Sum_{n>0} x^n*(1+x^n)/(1-x^n). - Franklin T. Adams-Watters, Oct 09 2009
MATHEMATICA
Table[2 DivisorSigma[0, n]-1, {n, 97}] (* Stefano Spezia, Sep 08 2023 *)
PROG
(PARI) N=66; x='x+O('x^N); /* that many terms */
Vec(sum(n=1, N, x^n*(1+x^n)/(1-x^n))) /* show terms */ /* Joerg Arndt, May 25 2011 */
(PARI) A114003(n) = (2*numdiv(n))-1; \\ After Jovovic's formula. Antti Karttunen, May 25 2017
CROSSREFS
Also row sums of triangle A144515. - Gary W. Adamson, Nov 21 2007
Sequence in context: A243729 A200810 A365710 * A219792 A029622 A015126
KEYWORD
nonn
AUTHOR
Paul Barry, Nov 12 2005
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 May 19 14:45 EDT 2024. Contains 372698 sequences. (Running on oeis4.)