OFFSET
1,4
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..47
FORMULA
EXAMPLE
a(0) = 0 since 2 is adjacent to 3 (exponent of 2nd Mersenne prime).
a(2) = 1 since 4 is between 3 and 5 (exponent of 3rd Mersenne prime).
a(3) = 1 since 6 is between 5 and 7 (exponent of 4th Mersenne prime).
a(4) = 5 since 8, 9, 10, 11, and 12 are between 7 and 13 (exponent 5th Mersenne prime).
MATHEMATICA
Differences[MersennePrimeExponent[Range[40]]]-1 (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 09 2020 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jani Melik, Mar 08 2009, Mar 09 2009
EXTENSIONS
a(39)-a(44) from Amiram Eldar, Oct 18 2024
STATUS
approved