|
%I #24 Feb 19 2023 16:27:56
%S 2,10,16,34,49,2570
%N Indices of the concatenation of the first n odd numbers (A019519) which are primes.
%C No others with n <= 12000. - _Eric W. Weisstein_, Mar 01 2004
%H H. Ibstedt, <a href="https://www.gallup.unm.edu/~smarandache/SN/SIntegerSeq.pdf">A Few Smarandache Integer Sequences</a>, Smarandache Notions Journal, Vol. 8, No. 1-2-3, 1997, pp. 171-183.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/ConsecutiveNumberSequences.html">Consecutive Number Sequences</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/IntegerSequencePrimes.html">Integer Sequence Primes</a>
%H <a href="/index/Mo#MWP">Index entries for sequences related to Most Wanted Primes video</a>
%F a(n) = (A066811(n)+1)/2. - _Michel Marcus_, Jan 31 2014
%t Module[{nn=50,odds},odds=Range[1,2nn+1,2];Position[Table[ FromDigits[ Flatten[IntegerDigits/@Take[odds,n]]],{n,nn}],_?(PrimeQ[#]&)]]// Flatten (* The program generates the first 5 terms of the sequence. To generate the 6th, increase the value of nn to 2570 or more, but the program will take a long time to run. *) (* _Harvey P. Dale_, Jul 21 2021 *)
%Y Cf. A019519, A048847.
%K nonn,base
%O 1,1
%A _Eric W. Weisstein_
|
