OFFSET
1,2
COMMENTS
The fixed points begin 1, 306, 13442, 24566, 30607, 53557, 65136; it is likely there are infinitely more. The sequence is conjectured to be a permutation of the positive integers, although it takes many terms for some values to appear, e.g., a(177950) = 9.
LINKS
Scott R. Shannon, Table of n, a(n) for n = 1..10000
EXAMPLE
a(2) = 13735 as a(1) = 1 and |13735-1| = 13734, 13735+1 = 13736, and soprf(13734) = 124 = soprf(13736), Omega(13734) = 5 = Omega(13736). No smaller number satisfies these requirements.
a(492) = 2 as a(491) = 427 and |427-2| = 425, 427+2 = 429, and soprf(425) = 27 = soprf(429), Omega(425) = 3 = Omega(429).
CROSSREFS
KEYWORD
nonn
AUTHOR
Scott R. Shannon, Feb 20 2024
STATUS
approved