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Prime times: primes of the form HMM with primes H, MM, 0<H<24, 0<MM<60.
8

%I #8 Mar 27 2022 15:58:13

%S 211,223,229,241,307,311,313,317,331,337,347,353,359,503,523,541,547,

%T 719,743,1103,1117,1123,1129,1153,1303,1307,1319,1723,1741,1747,1753,

%U 1759,1907,1913,1931,2311,2341,2347

%N Prime times: primes of the form HMM with primes H, MM, 0<H<24, 0<MM<60.

%C Suggested by E. Angelini, cf. link.

%H E. Angelini, in <a href="http://www.facebook.com/group.php?gid=40620217438">"Les membres de ce groupe forment un nombre premier"</a>, April 30, 2009.

%t Select[Flatten[Table[FromDigits[Join[IntegerDigits[h],PadLeft[ IntegerDigits[ m],2]]],{h,Prime[Range[9]]},{m,Prime[Range[ 17]]}]],PrimeQ] (* _Harvey P. Dale_, Mar 27 2022 *)

%o (PARI) forprime( h=0,24, forprime( m=0,60, isprime(100*h+m) & print1(100*h+m,", ")))

%Y See also A050246 and A229106, where H and MM (and SS) do not need to be prime.

%K base,dumb,easy,fini,full,nonn

%O 1,1

%A _M. F. Hasler_, May 01 2009