1,2

a(2) and a(3) certified prime with Primo. a(4) is a probable prime.

a(7) > 10^4.

Table of n, a(n) for n=1..6.

a(2)=122 because 12200...(121 zeros)...000221 is prime.

Sequence in context: A004925 A276303 A224598 * A195856 A116216 A203805

Adjacent sequences: A070952 A070953 A070954 * A070956 A070957 A070958

base,more,nonn

Jason Earls, May 25 2002

a(5), a(6) from Max Alekseyev, May 21 2011

approved