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

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A117836 Semiprimes of the form floor(e^k). 1
 403, 3269017, 485165195, 3584912846, 26489122129, 29048849665247, 639843493530054949, 114200738981568428366295718, 66631762164108958342448140502408732626873, 492345828601205839975486205911330449483779 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Giovanni Resta, Table of n, a(n) for n = 1..17 FORMULA a(n) = {floor(e^k) = p*q for integer k, p and q prime}. a(n) = A000149 INTERSECTION A001358. EXAMPLE a(1) = 403 = floor(e^6) = 13 * 31. a(2) = 3269017 = floor(e^15) = 773 * 4229. a(3) = 485165195 = floor(e^20) = 5 * 97033039. a(4) = 3584912846 = floor(e^22) = 2 * 1792456423. a(5) = 26489122129 = floor(e^24) = 103 * 257175943. CROSSREFS Cf. A000040, A000149, A001358, A074496. Sequence in context: A165808 A283662 A097741 * A185640 A185637 A234675 Adjacent sequences: A117833 A117834 A117835 * A117837 A117838 A117839 KEYWORD nonn AUTHOR Jonathan Vos Post, Apr 30 2006 EXTENSIONS a(6)-a(10) from Giovanni Resta, Jun 15 2016 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.

Last modified December 9 06:02 EST 2023. Contains 367685 sequences. (Running on oeis4.)