OFFSET
1,1
LINKS
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.
Richard G.E. Pinch, Economical numbers, arXiv:math/9802046 [math.NT], 1998
Carlos Rivera, Puzzle 53
Eric Weisstein's World of Mathematics, Economical Number
CROSSREFS
KEYWORD
nonn,base,hard,more
AUTHOR
Arkadiusz Wesolowski, Apr 15 2014
EXTENSIONS
a(5) found by Jens Kruse Andersen
STATUS
approved