login
A138841
Concatenation of initial and final digit of n-th Mersenne prime A000668(n).
8
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
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.
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