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A090257
a(1) = 1, then least square such that every partial concatenation is a prime.
0
1, 1, 81, 729, 441, 729, 81, 1521, 59049, 1521, 9, 13689, 1089, 159201, 62001, 363609, 4761, 1521, 8649, 1147041, 110889, 29241, 233289, 370881, 558009, 7569, 710649, 59049, 184041, 301401, 56169, 77841, 71289, 233289, 81, 91809, 1535121, 9018009
OFFSET
0,3
COMMENTS
a(n) == 0 (mod 9) for n>1. Conjecture: Sequence is infinite.
EXAMPLE
11,1181,1181729 etc. are primes.
CROSSREFS
Sequence in context: A232026 A133549 A235946 * A295233 A271829 A066431
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 27 2003
EXTENSIONS
More terms from David Wasserman, Oct 21 2005
STATUS
approved