OFFSET
1,2
COMMENTS
From Giovanni Resta, Feb 26 2020: (Begin)
a(19) = 87281795511221945137157107231920199501246882793017456359
1022443890274314214463840399002493765586034912718204488778054862
8428927680798004987531172069825436408977556109725685785536159601,
which is too large (184 digits) to be included in Data.
Here a(18)*a(19) = 245|a(19)|7 = 24587|a(18)|955... where | denotes digit concatenation. (End)
EXAMPLE
a(1)*a(2) = 1*10 = 10 and 10 contains the substrings 1 and 10, which are precisely a(1) and a(2);
a(17)*a(18) = 81*2817 = 228177 and 228177 contains the substrings 81 and 2817, which are precisely a(17) and a(18).
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini and Carole Dubois, Feb 24 2020
STATUS
approved