A138839 Concatenation of initial and final digits of n-th perfect number, divided by 2.

33, 14, 23, 44, 18, 43, 9, 14, 13, 8, 9, 9, 13, 9, 29, 9, 48, 18, 8, 24, 8, 28, 18, 48, 8, 43, 18, 9, 9, 8, 14, 9, 43, 44, 18, 8, 43, 48, 23

Offset: 1

Author

Omar E. Pol, Apr 02 2008

Keywords

• base
• easy
• nonn

Comments

Also, concatenation of A135617(n) and A094540(n), divided by 2.

Examples

			a(5)=18 because the 5th perfect number A000396(5) is 33550336 and the concatenation of initial and final digits of 33550336 is 36 and 36/2 = 18.
		

Crossrefs

Cf. A000396, A073729, A135617, A094540, A138843.