A367362 Comma transform of the nonnegative integers.

1, 12, 23, 34, 45, 56, 67, 78, 89, 91, 1, 11, 21, 31, 41, 51, 61, 71, 81, 92, 2, 12, 22, 32, 42, 52, 62, 72, 82, 93, 3, 13, 23, 33, 43, 53, 63, 73, 83, 94, 4, 14, 24, 34, 44, 54, 64, 74, 84, 95, 5, 15, 25, 35, 45, 55, 65, 75, 85, 96, 6, 16, 26, 36, 46, 56, 66, 76, 86, 97, 7, 17, 27, 37, 47, 57, 67, 77, 87, 98, 8, 18

Offset

0,2

Comments

See A367360 for further information.

Links

Michael S. Branicky, Table of n, a(n) for n = 0..10000

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

Formula

a(n) = 10 * A010879(n) + A000030(n+1). - Alois P. Heinz, Nov 22 2023

Maple

a:= n-> parse(cat(""||n[-1], ""||(n+1)[1])):
seq(a(n), n=0..99);  # Alois P. Heinz, Nov 22 2023

Mathematica

FromDigits /@ Partition[Rest@ Flatten[{First[#], Last[#]} & /@ IntegerDigits[Range[0, 120]]], 2, 2] (* Michael De Vlieger, Nov 22 2023 *)

Prog

(Python)
from itertools import count, islice, pairwise
def S(): yield from (str(i) for i in count(0))
def agen(): yield from (int(t[-1]+u[0]) for t, u in pairwise(S()))
print(list(islice(agen(), 82))) # Michael S. Branicky, Nov 22 2023
(Python)
def A367362(n): return (n%10)*10+int(str(n+1)[0]) # Chai Wah Wu, Dec 22 2023

Crossrefs

Cf. A000030, A010879, A166499, A367360, A367361, A368362.

Sequence in context: A029756 A346508 A104340 * A136414 A017401 A004960

Adjacent sequences: A367359 A367360 A367361 * A367363 A367364 A367365

Keyword

nonn,base

Author

N. J. A. Sloane, Nov 22 2023

Status

approved