This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A131463 Residues of 3^(2^p(n)) for Mersenne numbers with prime indices. 6
 0, 2, 9, 9, 929, 9, 9, 9, 2633043, 49618850, 9, 110361958311, 2072735666087, 1831797169511, 91222349803976, 1359811476184687, 504939123701081904, 9, 122453792873589376894, 623626925849389978443 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS M_p is prime iff 3^(M_p+1) is congruent to 9 mod M_p. Thus M_7 = 127 is prime because 3^128 mod 127 = 9 while M_11 = 2047 is composite because 3^2048 mod 2047 <> 9. LINKS Dennis Martin, Table of n, a(n) for n = 1..100 FORMULA a(n) = 3^(2^p(n)) mod 2^p(n)-1 EXAMPLE a(5) = 3^(2^11) mod 2^11-1 = 3^2048 mod 2047 = 929 CROSSREFS Cf. A095847, A001348, A131458, A131459, A131460, A131461, A131462. Sequence in context: A109322 A000587 A014182 * A065644 A043065 A077214 Adjacent sequences:  A131460 A131461 A131462 * A131464 A131465 A131466 KEYWORD nonn AUTHOR Dennis Martin (dennis.martin(AT)dptechnology.com), Jul 20 2007 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.