Search: id:A039997
Results 1-1 of 1 results found.

%I A039997
%S A039997 0,1,1,0,1,0,1,0,0,0,1,1,2,0,1,0,2,0,1,1,1,1,3,1,2,1,2,1,2,1,2,2,1,1,2,
%T A039997 1,3,1,1,0,1,1,2,0,1,0,2,0,0,1,1,2,3,1,1,1,2,1,2,0,1,1,1,0,1,0,2,0,0,1,
%U A039997 2,2,3,1,2,1,1,1,2,0,0,1,2,0,1,0,1,0,1,0,0,1,1,0,1,0,2,0,0,0,1,1,2,0,1
%N A039997 Number of distinct primes which occur as substrings of the digits of 
               n.
%C A039997 a(A062115(n))=0; a(A093301(n))=n and a(m)<>n for m<A093301(n). - Reinhard 
               Zumkeller (reinhard.zumkeller(AT)gmail.com), Jul 16 2007
%H A039997 R. Zumkeller, <a href="b039997.txt">Table of n, a(n) for n = 1..10000</
               a>
%e A039997 a(22)=1 because 22 has two substrings which are prime but they are identical. 
               a(103)=2, since the primes 3 and 103 occur as substrings.
%t A039997 a[n_] := Block[{s = IntegerDigits[n], c = 0, d = {}}, l = Length[s]; 
               t = Flatten[ Table[ Take[s, {i, j}], {i, 1, l}, {j, i, l}], 1]; k 
               = l(l + 1)/2; While[k > 0, If[ t[[k]][[1]] != 0, d = Append[d, FromDigits[ 
               t[[k]] ]]]; k-- ]; Count[ PrimeQ[ Union[d]], True]]; Table[ a[n], 
               {n, 1, 105}]
%Y A039997 Different from A039995 after the 100th term. Cf. A035232.
%Y A039997 Sequence in context: A131743 A147648 A113686 this_sequence A039995 A035232 
               A091603
%Y A039997 Adjacent sequences: A039994 A039995 A039996 this_sequence A039998 A039999 
               A040000
%K A039997 nonn,base
%O A039997 1,13
%A A039997 Dave Wilson
%E A039997 Edited by Robert G. Wilson v (rgwv(AT)rgwv.com), Feb 24 2003

Search completed in 0.001 seconds