A367347 a(1) = 1; thereafter, a(n+1) = a(n) + x + 10*y, where x and y are respectively the first and last digits of a(n).

1, 12, 33, 66, 132, 153, 184, 225, 277, 349, 442, 466, 530, 535, 590, 595, 650, 656, 722, 749, 846, 914, 963, 1002, 1023, 1054, 1095, 1146, 1207, 1278, 1359, 1450, 1451, 1462, 1483, 1514, 1555, 1606, 1667, 1738, 1819, 1910, 1911, 1922, 1943, 1974, 2015, 2067, 2139, 2231, 2243, 2275, 2327, 2399

Offset

1,2

Comments

This sequence and A367348 are simple models for the Commas sequence A121805.

Links

N. J. A. Sloane, Table of n, a(n) for n = 1..20000

Formula

a(888508) = A367348(837058) = 40000026, so a(888508+i) = A367348(837058+i) for i >= 0. - Michael S. Branicky, Nov 17 2023

Mathematica

NestList[#+First[IntegerDigits[#]]+10Mod[#, 10]&, 1, 100] (* Paolo Xausa, Nov 17 2023 *)

Prog

(Python)
from itertools import islice
def agen(): # generator of terms
    an = 1
    while True:
        yield an
        s = str(an)
        an += int(s[0]) + 10*int(s[-1])
print(list(islice(agen(), 55))) # Michael S. Branicky, Nov 17 2023

Crossrefs

Cf. A121805, A367348.

Sequence in context: A063296 A372027 A051624 * A039338 A118337 A032604

Adjacent sequences: A367344 A367345 A367346 * A367348 A367349 A367350

Keyword

nonn,base

Author

N. J. A. Sloane, Nov 16 2023

Status

approved