%I #18 Nov 06 2021 06:37:09

%S 2,5,64,1867,491851,17681491,35565206671,43194825904693

%N Start of first run of n successive numbers in which i-th number has exactly i distinct prime divisors for i = 1..n.

%D J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 64, p. 23, Ellipses, Paris 2008.

%e a(3) = 64, as 64 has 1, 65 has 2 and 66 has 3 prime divisors: 64 = 2^6, 65 = 5*13 and 66 = 2*3*11.

%Y Cf. A001221, A072875.

%K nonn,hard,more

%O 1,1

%A _Amarnath Murthy_, Aug 30 2003

%E More terms from _Don Reble_, Sep 13 2003

%E a(7) from _Donovan Johnson_, Mar 06 2008

%E a(8) from _Donovan Johnson_, Jul 19 2011