login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A082126 Smallest difference>1 between d and p/d for any divisor d of the partial product p of the sequence, starting with 19. 2
19, 18, 29, 27, 9, 27, 2187, 6561, 531441, 387420489, 7625597484987, 328256967394537077627, 381520424476945831628649898809, 235655016338368235499067731945871638181119123 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Except for the first three, the members are all powers of 3. Proved by Luke Pebody, pers. comm.

LINKS

Table of n, a(n) for n=0..13.

PROG

(PARI) p=19; print1(p, ", "); for(n=1, 50, v=divisors(p); r=sqrt(p); t=0; for(k=1, matsize(v)[2], if(v[k]>=r, t=k; break));  if(v[t]^2==p, u=t, u=t-1);  if(v[t]-v[u]<2, u=u-1; t=t+1); print1(v[t]-v[u]", "); p=p*(v[t]-v[u]))

CROSSREFS

Cf. A082120, A003681 (starts with 2, 3), A082128.

Sequence in context: A023461 A305238 A004460 * A176411 A131382 A291475

Adjacent sequences:  A082123 A082124 A082125 * A082127 A082128 A082129

KEYWORD

nonn

AUTHOR

Ralf Stephan, Apr 04 2003

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 October 16 18:38 EDT 2019. Contains 328102 sequences. (Running on oeis4.)