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!)
A155053 Primes n with nonprime smallest digit of prime(n). 2

%I #18 Mar 29 2014 05:21:33

%S 5,7,11,13,19,29,31,37,41,43,47,53,67,79,83,89,97,101,113,127,157,163,

%T 167,173,179,181,191,193,197,199,211,223,227,229,233,239,241,251,257,

%U 263,269,271,277,281,283,293,307,311,313,317,331,347,349,353,359,379,397,409,421,431,433,439,443,449,467,479,491,523,541,557,563,569,571,577,601,613,617,619,641,643,647,653,673,677,683,691,701,709,719,727,743,751,757,761,769

%N Primes n with nonprime smallest digit of prime(n).

%H Vincenzo Librandi, <a href="/A155053/b155053.txt">Table of n, a(n) for n = 1..1000</a>

%e a(1) = 5 corresponds to the fact that the fifth prime is 11, the smallest digit of which is 1, which is nonprime.

%e a(2) = 7: the seventh prime is 17, the smallest digit of which is 1, which is nonprime.

%e a(3) = 11: the eleventh prime is 31, the smallest digit of which is 1, which is, again, nonprime.

%t Select[Prime[Range[150]], !PrimeQ[Min[IntegerDigits[Prime[#]]]] &] (* _Harvey P. Dale_, Nov 25 2010 *)

%Y Cf. A154981.

%K nonn,base,less

%O 1,1

%A _Juri-Stepan Gerasimov_, Jan 19 2009

%E Corrected (19 inserted, 1673 replaced by 167) by _R. J. Mathar_, May 05 2010

%E More terms from _Harvey P. Dale_, Nov 25 2010

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 16:34 EDT 2024. Contains 371254 sequences. (Running on oeis4.)