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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A158035 2 * A158034 + 1, prime numbers p for which f = (2^p - 2^((p - 1) / 2 + 1) + 4p^2 - 8p) / (2p^2 - 2p) is an integer. 8
 7, 23, 47, 167, 263, 359, 383, 479, 487, 503, 719, 839, 863, 887, 983, 1319, 1367, 1439, 1487, 1783, 1823, 2039, 2063, 2207, 2447, 2879, 2903, 2999, 3023, 3079, 3119, 3167, 3623, 3863, 4007, 4079, 4127, 4423, 4679, 4703, 4799, 4919, 5023, 5087, 5399, 5639 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS (p - 1) / 2 is often prime. LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 MAPLE A158035 := proc(n) local i, am, p, tren; am := [ ]: for i from 2 to n do p := ithprime(i): tren := (2^(p) - 2^((p - 1) / 2 + 1) + 4*p^(2) - 8*p) / (2*p^(2) - 2*p): if (type( tren, 'integer') = 'true') then am := [op(am), p]: fi od; RETURN(am) end: A158035(740); # Jani Melik, May 06 2013 MATHEMATICA Select[Prime[Range[800]], IntegerQ[(2^#-2^((#-1)/2+1)+4#^2-8#)/(2#^2-2#)]&] (* Harvey P. Dale, Nov 08 2017 *) CROSSREFS Cf. A158034. Cf. A002515 (Lucasian primes). Cf. A145918 (exponential Sophie Germain primes). Cf. A046318, A139876 (related to composite members of A158034: 243, 891, 1539, and 2511). Sequence in context: A139830 A153210 A185955 * A101789 A174590 A162290 Adjacent sequences: A158032 A158033 A158034 * A158036 A158037 A158038 KEYWORD easy,nonn AUTHOR Reikku Kulon, Mar 11 2009 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 May 25 17:00 EDT 2024. Contains 372804 sequences. (Running on oeis4.)