OFFSET
1,2
COMMENTS
The sequence is conjectured to be a permutation of the positive integers.
LINKS
Scott R. Shannon, Image of the first 75000 terms. The green line is y = n.
EXAMPLE
a(15) = 27 as a(14) = 10, and 27 has not yet appeared, is coprime to 10, is not 1 more than 10, and has no digit in common with 10. Note that 21 satisfies all of these conditions except the last. This is the first term to differ from A353904.
PROG
(Python)
from math import gcd
from itertools import islice
def c(san, k): return set(san) & set(str(k)) == set()
def agen(): # generator of terms
an, aset, mink = 1, {1}, 2
while True:
yield an
k, san = mink, str(an)
while k in aset or gcd(an, k) != 1 or k-an == 1 or not c(san, k):
k += 1
an = k
aset.add(an)
while mink in aset: mink += 1
print(list(islice(agen(), 75))) # Michael S. Branicky, May 23 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Scott R. Shannon, May 07 2022
STATUS
approved