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A104323 Primes which are the reverse concatenation of four consecutive numbers. 1

%I #8 Aug 02 2021 18:40:09

%S 10987,22212019,86858483,94939291,100999897,106105104103,112111110109,

%T 122121120119,124123122121,146145144143,184183182181,226225224223,

%U 232231230229,244243242241,274273272271,332331330329,362361360359

%N Primes which are the reverse concatenation of four consecutive numbers.

%H Zak Seidov, <a href="/A104323/b104323.txt">Table of n, a(n) for n = 1..328</a>

%e The first term is 10987 which is a prime and is the reverse concatenation of 7,8,9 and 10 which are four consecutive numbers.

%t Select[Table[FromDigits[Flatten[IntegerDigits/@Range[n,n-3,-1]]],{n,4,400}],PrimeQ] (* _Harvey P. Dale_, Aug 02 2021 *)

%o (PARI) forstep(n=10,400,2,isprime(t=eval(Str(n,n-1,n-2,n-3)))&print1(t",")) \\ _Zak Seidov_, May 08 2013

%Y Cf. A052089.

%K base,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Apr 17 2005

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Last modified May 18 02:23 EDT 2024. Contains 372617 sequences. (Running on oeis4.)