A138841 Concatenation of initial and final digit of n-th Mersenne prime A000668(n).

33, 77, 31, 17, 81, 11, 57, 27, 21, 61, 17, 17, 61, 57, 17, 17, 41, 21, 11, 27, 41, 31, 21, 41, 41, 41, 81, 57, 57, 51, 77, 17, 11, 47, 81, 61, 11, 41, 91, 17, 27, 17, 31, 11, 27, 11, 31

Offset

1,1

Links

Table of n, a(n) for n=1..47.

Formula

a(n) = A073729(A000668(n)). - Michel Marcus, Apr 17 2018

Example

a(5)=81 because the 5th Mersenne prime is 8191, A000668(5)=8191.

Crossrefs

Cf. A000668, A073729, A080172, A135613, A138840, A138842, A138843.

Sequence in context: A137187 A354916 A134037 * A248979 A246409 A378481

Adjacent sequences: A138838 A138839 A138840 * A138842 A138843 A138844

Keyword

base,nonn,more,less

Author

Omar E. Pol, Apr 01 2008

Extensions

a(40)-a(47) from Ivan Panchenko, Apr 17 2018

Status

approved