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

Author

N. J. A. Sloane, Nov 16 2023

Keywords

• nonn
• base

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

Crossrefs

Cf. A121805, A367348.

Programs

Mathematica

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

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

Formula

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