A138838 Concatenation of initial and final digits of n-th even superperfect number A061652(n), divided by 2.

11, 22, 8, 32, 23, 33, 12, 7, 8, 18, 42, 42, 18, 12, 27, 37, 13, 8, 48, 7, 13, 8, 8, 13, 13, 13, 23, 12, 12, 13, 17, 42, 33, 12, 23, 18, 33, 13, 23, 32, 7, 32, 8, 33, 7, 43, 8

Offset: 1

Author

Omar E. Pol, Apr 02 2008

Keywords

• nonn
• base
• more

Comments

Also, concatenation of initial and final digits of n-th superperfect number A019279(n), divided by 2, if there are no odd superperfect numbers.

Also, concatenation of A138124(n) and A138125(n), divided by 2.

Examples

			a(5)=23 because the 5th even superperfect number A061652(5) is 4096 and the concatenation of initial and final digits of 4096 is 46 and 46/2 = 23.
		

Crossrefs

Cf. A019279, A061652, A073729, A138124, A138125, A138842.

Formula

a(n) = A138842(n)/2. - Jinyuan Wang, Mar 14 2020

Extensions

More terms from Jinyuan Wang, Mar 14 2020