This site is supported by donations to The OEIS Foundation.

 Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS". Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A031926 Lower prime of a difference of 8 between consecutive primes. 19
 89, 359, 389, 401, 449, 479, 491, 683, 701, 719, 743, 761, 911, 929, 983, 1109, 1163, 1193, 1373, 1439, 1523, 1559, 1571, 1733, 1823, 1979, 2003, 2153, 2213, 2243, 2273, 2459, 2531, 2609, 2663, 2699, 2741, 2843, 2879, 2909, 3011, 3041 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Conjecture: The sequence is infinite and for every n, a(n+1) < a(n)^(1+1/n). Namely a(n)^(1/n) is a strictly decreasing function of n (See comment lines of the sequence A248855). - Jahangeer Kholdi and Farideh Firoozbakht, Nov 29 2014 LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 MAPLE for i from 1 to 446 do if ithprime(i+1) = ithprime(i) + 8 then print({ithprime(i)}); fi; od; # Zerinvary Lajos, Mar 19 2007 p:=ithprime; nx:=nextprime; f:=proc(d) global p, nx; local i, t0, n; t0:=[]; for n from 1 to 100000 do i:=p(n); if nx(i)-i=d then t0:=[op(t0), i]; fi; od: t0; end; f(8); # N. J. A. Sloane, Jan 17 2012 MATHEMATICA Transpose[Select[Partition[Prime[Range[500]], 2, 1], Last[#] - First[#] == 8 &]][[1]] (* Bruno Berselli, Apr 09 2013 *) PROG (MAGMA) [p: p in PrimesUpTo(4000) | NextPrime(p)-p eq 8]; // Bruno Berselli, Apr 09 2013 (PARI) is_A031926(p)={precprime(p-1)==p-8 && isprime(p)} \\ - M. F. Hasler, Apr 20 2013 (PARI) q=0; forprime(p=1, 5000, q+8==(q=p)&&print1(p-8", ")) \\ - M. F. Hasler, Apr 20 2013 CROSSREFS Cf. A023202. Sequence in context: A142685 A140772 A142292 * A132253 A288024 A118922 Adjacent sequences:  A031923 A031924 A031925 * A031927 A031928 A031929 KEYWORD nonn AUTHOR 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.