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

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A083472 Smallest prime p such that the backward concatenation of n consecutive decreasing primes starting with p is a prime. 1

%I

%S 2,5,29,59,37,17,193,59,167,149,103,563,109,107,149,317,409,829,283,

%T 263,467,107,89,3181,313,113,431,521,739,577,487,617,1601,937,167,991,

%U 2699,293,1481,3593,4943,593,541,673,241,719,1217,449,421,1667,337,353,1297

%N Smallest prime p such that the backward concatenation of n consecutive decreasing primes starting with p is a prime.

%e a(3) = 29 as the concatenation of 29,23 and 19, i.e. 292319, is a prime.

%t bcpQ[n_]:=PrimeQ[FromDigits[Flatten[IntegerDigits/@Reverse[n]]]]; With[{prs = Prime[ Range[10000]]},Table[Select[Partition[prs,n,1],bcpQ,1][[1,-1]],{n,60}]] (* _Harvey P. Dale_, Aug 12 2013 *)

%Y Cf. A083471.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_ and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 02 2003

%E More terms from _David Wasserman_, Nov 15 2004

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 26 23:54 EST 2022. Contains 350601 sequences. (Running on oeis4.)