OFFSET
1,2
COMMENTS
LINKS
Rémy Sigrist, Colored scatterplot of (n, a(n)) for n = 1..10000 (where the color corresponds to the parity of a(n): red for odd, blue for even)
Rémy Sigrist, Colored scatterplot of (n, a(n)-n) for n = 1..1000000 (where the color corresponds to the parity of a(n)-n: red for odd, blue for even)
Rémy Sigrist, PARI program for A306581
EXAMPLE
The first terms, alongside their binary representations, and the concatenation of consecutive terms, with prime numbers denoted by a star, are:
n a(n) bin(a(n)) bin(a(n)a(n+1)) bin(a(n+1)a(n))
-- ---- --------- --------------- ---------------
1 1 1 110 101*
2 2 10 1011* 1110
3 3 11 11100 10011*
4 4 100 100101* 101100
5 5 101 101110 110101*
6 6 110 1101011* 1011110
7 11 1011 10111000 10001011*
8 8 1000 1000111* 1111000
9 7 111 1111001 1001111*
10 9 1001 10011101* 11011001
PROG
(PARI) See Links section.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Rémy Sigrist, Feb 25 2019
STATUS
editing