login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A367612
Numbers that are the comma-child of exactly one positive number.
2
11, 12, 22, 23, 24, 33, 34, 35, 36, 44, 45, 46, 47, 48, 55, 56, 57, 58, 59, 60, 61, 66, 67, 68, 69, 70, 71, 72, 73, 77, 78, 79, 80, 81, 82, 83, 84, 85, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122
OFFSET
1,1
COMMENTS
This is the complement of A367611.
See A367338 for definition of comma-child.
May also be called numbers that have a positive comma-predecessor.
LINKS
Eric Angelini, Michael S. Branicky, Giovanni Resta, N. J. A. Sloane, and David W. Wilson, The Comma Sequence: A Simple Sequence With Bizarre Properties, arXiv:2401.14346, Youtube
PROG
(Python)
def ok(n): y = int(str(n)[0]); x = (n-y)%10; return n - y - 10*x > 0
print([k for k in range(1, 123) if ok(k)]) # Michael S. Branicky, Dec 15 2023
CROSSREFS
Sequence in context: A231871 A192287 A084855 * A367340 A101233 A118512
KEYWORD
nonn,base
AUTHOR
STATUS
approved