login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A091515 Indices n of Carol (or near-square) primes: numbers n such that (2^n-1)^2-2 = 4^n-2^{n+1}-1 is prime. 10
2, 3, 4, 6, 7, 10, 12, 15, 18, 19, 21, 25, 27, 55, 129, 132, 159, 171, 175, 315, 324, 358, 393, 435, 786, 1459, 1707, 2923, 6462, 14289, 39012, 51637, 100224, 108127, 110953, 175749, 185580, 226749, 248949, 253987 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

Steven Harvey, Carol and Kynea Primes.

Eric Weisstein's World of Mathematics, Near-Square Prime

Eric Weisstein's World of Mathematics, Integer Sequence Primes

MATHEMATICA

lst={}; Do[p=(2^n-1)^2-2; If[PrimeQ[p], AppendTo[lst, n]], {n, 7!}]; lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jan 27 2009]

CROSSREFS

Cf. A093112 (Carol numbers), A091516 (Carol primes).

Sequence in context: A049806 A158381 A163180 * A036405 A051424 A137606

Adjacent sequences:  A091512 A091513 A091514 * A091516 A091517 A091518

KEYWORD

nonn,hard

AUTHOR

Eric Weisstein (eric(AT)weisstein.com), Jan 17, 2004

EXTENSIONS

More terms from Pab Ter (pabrlos(AT)yahoo.com), May 25 2004

a(36)=175749 from Cletus Emmanuel (cemmanu(AT)yahoo.com), Oct 08 2004

a(37)=185580 from Cletus Emmanuel (cemmanu(AT)yahoo.com), Nov 03 2004

Edited by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 15, 2004

a(38)=226749 from Steven Harvey (harvey563(AT)yahoo.com), Jan 11 2005 and subsequently confirmed as next term.

a(39) from Eric Weisstein (eric(AT)weisstein.com), Mar 31, 2006

a(40)=253987 from Cletus Emmanuel (cemmanu(AT)yahoo.com), May 03 2007

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 23:39 EST 2012. Contains 206085 sequences.