A147800 Minimal value of A007947(m*(5^n-m)) with m coprime to 5.

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

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, (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: A350553 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