

A047738


Earliest sequence of 4 consecutive economical numbers.


1




OFFSET

1,1


LINKS

Table of n, a(n) for n=1..4.
Tanya Khovanova, Non Recursions
J.M. De Koninck and F. Luca, On strings of consecutive economical numbers of arbitrary length, Integers: Electronic Journal of Combinatorial Number Theory 5, (2005), #A5.
Eric Weisstein's World of Mathematics, Economical Number


EXAMPLE

179210312 = 2^3* 4733^2; 9 digits in 179219312, 7 digits in its prime factorization, 7 < 9, so that number is economical.


CROSSREFS

Cf. A046759.
Sequence in context: A213966 A206520 A127955 * A079323 A228760 A204529
Adjacent sequences: A047735 A047736 A047737 * A047739 A047740 A047741


KEYWORD

fini,full,nonn,base


AUTHOR

Carlos Rivera


STATUS

approved



