A069846 - OEIS

%I #4 Dec 05 2013 19:55:18

%S 0,0,1,0,0,0,0,0,1,0,1,0,0,0,0,0,1,0,0,0,2,0,1,0,0,0,1,0,0,0,0,0,1,0,

%T 0,0,0,0,1,0,1,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,2,0,0,0,0,0,

%U 2,0,2,0,0,0,0,0,2,0,0,0,0,0,1,0,0,0,2,0,1,0,0,0,2,0,0,0,0,0,1,0,2,0,0,0,0

%N Number of distinct primes obtained by inserting a 5 at all possible places in n. This includes prefixing.

%e See the example in A069842.

%t Table[ Count[ PrimeQ[ Union[ FromDigits /@ Table[ Insert[ IntegerDigits[n], 5, j], {j, 1, Floor[ Log[10, n] + 2]}]]], True], {n, 1, 105}]

%Y Cf. A069842, A069843, A069844, A069845, A069847, A069848, A069849, A069850 and A069851.

%K base,nonn

%O 1,21

%A _Amarnath Murthy_, Apr 16 2002

%E Edited and extended by _Robert G. Wilson v_, Apr 18 2002