OFFSET
1,2
COMMENTS
a(n) - a(n+k) = k with k odd is forbidden as this would lead to a contradiction. This is why a(4) = 5 here and not a(4) = 3.
The sequence is a permutation of the natural numbers.
EXAMPLE
S = 1, 2, 4, 5, 3, 6, 7, 9, 10, 8, 11, 12, 13, ...
sum = 5 5 13 13 13 19
a(1) = 1 and 1 + 4 = 5 (prime)
a(2) = 2 and 2 + 3 = 5 (prime)
a(3) = 4 and 4 + 9 = 13 (prime)
a(4) = 5 and 5 + 8 = 13 (prime)
a(5) = 3 and 3 + 10 = 13 (prime)
a(6) = 6 and 6 + 13 = 19 (prime), etc.
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric Angelini, May 10 2023
EXTENSIONS
a(22) and beyond from Michael S. Branicky, May 10 2023
STATUS
approved