OFFSET
1,1
COMMENTS
a(n) is the rank of prime(n) in the base-4 dominance order on the natural numbers.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Tyler Ball and Daniel Juda, Dominance over N, Rose-Hulman Undergraduate Mathematics Journal, Vol. 13, No. 2, Fall 2013.
EXAMPLE
The sixth prime is 13, 13 in base 4 is (3,1) so a(6)=3+1=4.
MATHEMATICA
Table[Plus @@ IntegerDigits[Prime[n], 4], {n, 1, 100}] (* Vincenzo Librandi, Mar 25 2014 *)
PROG
(Sage) [sum(i.digits(base=4)) for i in primes_first_n(200)]
(Magma) [&+Intseq(NthPrime(n), 4): n in [1..100]]; // Vincenzo Librandi, Mar 25 2014
(Haskell)
a239690 = a053737 . a000040 -- Reinhard Zumkeller, Mar 20 2015
CROSSREFS
KEYWORD
AUTHOR
Tom Edgar, Mar 24 2014
STATUS
approved