A138817 Concatenation of final digit of n-th Mersenne prime A000668(n), final digit of n-th even superperfect number A061652(n) and final digit of n-th perfect number A000396(n).

326, 748, 166, 748, 166, 166, 748, 748, 166, 166, 748, 748, 166, 748, 748, 748, 166, 166, 166, 748, 166, 166, 166, 166, 166, 166, 166, 748, 748, 166, 748, 748, 166, 748, 166, 166, 166, 166, 166

Offset: 1

Author

Omar E. Pol, Apr 01 2008

Keywords

• base
• nonn
• less

Comments

Also, concatenation of final digit of n-th Mersenne prime A000668(n), final digit of n-th superperfect number A019279(n) and final digit of n-th perfect number A000396(n), if there are no odd superperfect numbers.

Also, concatenation of n-th term of A080172, A138125(n) and A094540(n).

a(1)=326. For n>1 a(n) is equal to 166 or 748, only.

Links

• L. C. Noll, Mersenne Prime Digits and Names.
• Omar E. Pol, Determinacion geometrica de los numeros primos y perfectos.

Crossrefs

Cf. A000396, A000668, A019279, A061652, A080172, A094540, A138125, A138817.