Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A064397
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
%I A064397
%S A064397 7,15,20,61,152,190,293,377,492,558,789,919,942,1768,2343,2429,2693,
%T A064397 2952,3136,3720,4837,5421,5722,6870,7347,8126,8193,9465,9857,9927,
%U A064397 10410,10483,10653,12685,13763,13955,16033,16342,17859,18367,18474
%N A064397 Numbers n such that p(n) + p(n+1) is a square. p(n) is n-th prime.
%H A064397 Zak Seidov, <a href="b064397.txt">Table of n, a(n) for n=1..1000</a>
%e A064397 n=15: prime(15) = 47 and prime(16) = 53, 47+53 = 100 = 10^2.
%t A064397 lst={};Do[p1=Prime[n];p2=Prime[n+1];q=(p1+p2)^0.5;If[q==IntegerPart[q], 
               AppendTo[lst, n]], {n, 1, 9!}];lst [From Vladimir Orlovsky (4vladimir(AT)gmail.com), 
               Sep 02 2008]
%o A064397 (PARI) j=[]; for(n=1,30000,x=prime(n)+prime(n+1); if(issquare(x),j=concat(j,
               n))); j
%o A064397 (PARI) { n=0; default(primelimit, 8500000); for (m=1, 10^9, if (issquare(prime(m) 
               + prime(m + 1)), write("b064397.txt", n++, " ", m); if (n==175, break)) 
               ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 13 2009]
%Y A064397 Sequence in context: A138641 A115783 A140109 this_sequence A151971 A014659 
               A053354
%Y A064397 Adjacent sequences: A064394 A064395 A064396 this_sequence A064398 A064399 
               A064400
%K A064397 nonn
%O A064397 1,1
%A A064397 Jason Earls (zevi_35711(AT)yahoo.com), Sep 29 2001

    
page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 17 19:39 EST 2009. Contains 170821 sequences.


AT&T Labs Research