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A147803 Least m coprime to 5 minimizing A007947(m*(5^n-m)). 5
1, 1, 4, 49, 128, 9, 36864, 19332, 4508, 121, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
The minima are given in A147800.
This is related to the abc conjecture: Since m is coprime to 5, it is also coprime to 5^n and thus to 5^n-m. Thus the squarefree kernel A007947(m*(5^n-m)*5^n) = 5*A007947(m*(5^n-m)).
LINKS
PROG
(PARI) A147803(n, p=5) = {my(b, m=n=p^n); for(a=1, n\2, a%p || next; A007947(n-a)*A007947(a)<m || next; m=A007947((n-a)*b=a)); b; }
CROSSREFS
Cf. A007947, A147298 (general case), A147800 (value of minima), A143700 (analog for 2^n), A147802 (analog for 3^n), A147300 (analog for any number).
Sequence in context: A136196 A222960 A061100 * A112533 A016874 A360883
KEYWORD
nonn,more
AUTHOR
M. F. Hasler, Nov 13 2008
STATUS
approved

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Last modified March 29 07:27 EDT 2024. Contains 371265 sequences. (Running on oeis4.)