A095347 n sets a new record for number of iterations of A034690 (sum of digits of the divisors of n) needed to reach 15 (see A086793).

2, 5, 9, 10, 16, 18, 34, 36, 66, 162, 924, 71820, 127005777360

Offset

1,1

Comments

323203999999676796 takes 22 iterations to reach 15, but it probably is not the next term.

One could prefix a(0)=1 and change the definition to "... reach a fixed point, 1 or 15." - M. F. Hasler, Nov 08 2015

Links

Table of n, a(n) for n=1..13.

Eric Angelini et al., List the dividers [sic], sum the digits, lost messages reconstructed by N. J. A. Sloane, Dec 21 2024

Prog

(PARI) m=0; for(n=1, 9e9, A086793(n)>m||next; m=A086793(n); print1(n", "))

Crossrefs

Cf. A034690, A086793, A094501.

Sequence in context: A376848 A191171 A191776 * A249353 A224866 A348167

Adjacent sequences: A095344 A095345 A095346 * A095348 A095349 A095350

Keyword

more,nonn,base

Author

Jason Earls, Jun 03 2004

Extensions

Offset corrected and a(13) from Donovan Johnson, Oct 28 2010

Status

approved