This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A090814 a(n)=3*(3^prime(n)-1)/denominator(B(2*prime(n))) where prime(n)=n-th prime and B(k) denotes the k-th Bernoulli number. 1
 11, 1093, 3851, 797161, 64570081, 581130733, 1001523179, 581613367499, 308836698141973, 225141952945498681, 219716845645607147, 164128483697268538813, 13294407179478751643893, 90575914334953364003723 (list; graph; refs; listen; history; text; internal format)
 OFFSET 3,1 COMMENTS Appears to be an integer for n from 3 up to 250. LINKS PROG (PARI) a(n)=3*(3^prime(n)-1)/denominator(bernfrac(2*prime(n))) CROSSREFS Sequence in context: A004811 A227323 A126197 * A319424 A153435 A266787 Adjacent sequences:  A090811 A090812 A090813 * A090815 A090816 A090817 KEYWORD nonn AUTHOR Benoit Cloitre, Feb 11 2004 STATUS approved

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

Last modified December 13 12:49 EST 2018. Contains 318086 sequences. (Running on oeis4.)