

A147800


Minimal value of A007947(m*(5^nm)) with m coprime to 5.


6



2, 6, 22, 42, 222, 366, 2046, 13962, 10626, 79926, 293262
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OFFSET

1,1


COMMENTS

The minima are reached for m values given in A147803.
This is related to the abc conjecture.
All terms of this sequence are even, so one could also consider A147800/2 = 1, 3, 11, 21, 111, 183, 1023, 6981, 5313, 39963, 146631, ...


LINKS

Table of n, a(n) for n=1..11.


PROG

(PARI) A147800(n, p=5) = {my(m=n=p^n); for(a=1, (n1)\2, a%p  next; A007947(na)*A007947(a)<m  next; m=A007947((na)*a)); m; }


CROSSREFS

Cf. A007947, A147803 (m values), A143702 (analog for 2^n), A147801 (analog for 3^n), A147298 (general case).
Sequence in context: A284632 A325020 A335131 * A246624 A212872 A306967
Adjacent sequences: A147797 A147798 A147799 * A147801 A147802 A147803


KEYWORD

nonn,more


AUTHOR

M. F. Hasler, Nov 13 2008


STATUS

approved



