Search: id:A124874 Results 1-1 of 1 results found. %I A124874 %S A124874 0,1,1,3,2,3,3,2,3,4,3,2,3,2,1,3,2,4,1,3,2,5,2,4,2,1,3,4 %N A124874 Number of primes dividing A007408(n). %e A124874 a(1) = 0 since no prime divides A007408(1)=1, %e A124874 a(2) = 1 since 3 is the only prime dividing A007408(2)=9, %e A124874 a(3) = 1 since A007408(3)=251 is prime, %e A124874 a(4) = 3 since A007408(4)=5 x 11 x 37, %e A124874 a(6) = 3 since 7,11,53 are the only primes dividing A007408(6)=7^2 x 11 x 53. %p A124874 seq( (nops@op)(2,(ifactors@A007408)(n)),n=1..25); %Y A124874 Cf. A007408, A124876, A124877. %Y A124874 Sequence in context: A153092 A165601 A054263 this_sequence A016459 A060585 A114451 %Y A124874 Adjacent sequences: A124871 A124872 A124873 this_sequence A124875 A124876 A124877 %K A124874 hard,nonn %O A124874 1,4 %A A124874 M. F. Hasler (Maximilian.Hasler(AT)gmail.com), Nov 11 2006 Search completed in 0.001 seconds