A230102 a(0)=1; thereafter a(n+1) = a(n) + (product of digits of a(n)).

1, 2, 4, 8, 16, 22, 26, 38, 62, 74, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102, 102

Offset

0,2

Comments

Never gets above 102.

Links

Table of n, a(n) for n=0..50.

Index entries for Colombian or self numbers and related sequences

Index entries for periodic sequences.

Index entries for linear recurrences with constant coefficients, signature (1).

Formula

a(n) = 102 for n > 9. - Charles R Greathouse IV, May 26 2026

Mathematica

NestList[#+Times@@IntegerDigits[#]&, 1, 50] (* Harvey P. Dale, Jul 30 2023 *)

Prog

(Haskell)
a230102 n = a230102_list !! n
a230102_list = iterate a230099 1  -- Reinhard Zumkeller, Oct 13 2013
(PARI) a(n)=if(n>9, 102, [1, 2, 4, 8, 16, 22, 26, 38, 62, 74][n+1]) \\ Charles R Greathouse IV, May 26 2026

Crossrefs

Cf. A007954, A051801, A063108, A230099, A232485.

Sequence in context: A045844 A254062 A341817 * A063108 A161140 A257350

Adjacent sequences: A230099 A230100 A230101 * A230103 A230104 A230105

Keyword

nonn,base,easy,changed

Author

N. J. A. Sloane, Oct 12 2013

Status

approved