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

1,1

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

Table of n, a(n) for n=1..39.

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.

Sequence in context: A031516 A066128 A138816 * A158271 A203723 A097737

Adjacent sequences: A138814 A138815 A138816 * A138818 A138819 A138820

Keyword

base,nonn,less

Author

Omar E. Pol, Apr 01 2008

Status

approved