login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A317399 Positive integers that have exactly nine representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes. 2
7021, 7162, 8053, 8737, 9178, 9556, 10126, 10858, 10861, 10866, 11113, 11133, 11363, 11740, 12076, 12111, 12666, 13168, 13210, 13339, 13573, 13729, 14037, 14366, 14411, 14691, 15250, 15478, 15569, 15653, 15726, 15922, 16066, 16113, 16116, 16386, 16459, 16644 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..20000

FORMULA

A317241(a(n)) = 9.

MAPLE

b:= proc(n, s) option remember; local p, r; if n=1 then 1 else r:=0;

      for p in numtheory[factorset](n-1) minus s while r<10

        do r:= r+b((n-1)/p, s union {p}) od; `if`(r<10, r, 10)

      fi

    end:

a:= proc(n) option remember; local k; for k from

     `if`(n=1, 1, 1+a(n-1)) while b(k, {})<>9 do od; k

    end:

seq(a(n), n=1..100);

CROSSREFS

Column k=9 of A317390.

Cf. A317241.

Sequence in context: A100897 A206757 A236061 * A116278 A206050 A116332

Adjacent sequences:  A317396 A317397 A317398 * A317400 A317401 A317402

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Jul 27 2018

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 12 22:46 EDT 2020. Contains 335669 sequences. (Running on oeis4.)