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A147800 Minimal value of A007947(m(5^n-m)) with m coprime to 5. 4
2, 6, 22, 42, 222, 366, 2046, 13962, 10626, 79926, 293262 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The minima are reached for m values given in A147803.

This is related to the abc conjecture, see also A143702, A147801 (2^n, 3^n analogs) and A147298 (general case).

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)={local(m=n=p^n); for(a=1, (n-1)\2, a%p|next; A007947(n-a)*A007947(a)<m|next; m=A007947((n-a)*a)); m}

CROSSREFS

Cf. A007947, A147803 (m values), A143702 (analog for 2^n), A147801 (analog for 3^n), A147298 (general case).

Sequence in context: A062085 A284632 A325020 * A246624 A212872 A306967

Adjacent sequences:  A147797 A147798 A147799 * A147801 A147802 A147803

KEYWORD

more,nonn

AUTHOR

M. F. Hasler, Nov 13 2008

STATUS

approved

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Last modified April 4 07:32 EDT 2020. Contains 333213 sequences. (Running on oeis4.)