OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
EXAMPLE
a(1)=2 because 2 = 10_2 and |{10, 01}| = 2,
a(2)=1 because 3 = 11_2 and |{11}| = 1,
a(3)=3 because 5 = 101_2 and |{101, 011, 110}| = 3.
MAPLE
A177687 := proc(n) p := ithprime(n) ; combinat[numbperm](convert(p, base, 2)) ; end proc: seq(A177687(n), n=1..120) ; # R. J. Mathar, May 15 2010
MATHEMATICA
Array[Length@ Permutations@ IntegerDigits[Prime@ #, 2] &, 72] (* Michael De Vlieger, Feb 15 2019 *)
CROSSREFS
KEYWORD
AUTHOR
Juri-Stepan Gerasimov, May 12 2010, May 14 2010
EXTENSIONS
Terms corrected by D. S. McNeil and R. J. Mathar, May 14 2010
STATUS
approved