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A215477 Semiprimes with consecutive (ascending) digits. 2

%I

%S 4,6,9,34,123,789,901,1234,34567,56789,901234,1234567,7890123,

%T 567890123,12345678901,345678901234567,4567890123456789,

%U 12345678901234567,890123456789012345,3456789012345678901,456789012345678901234,123456789012345678901234567,1234567890123456789012345678901,23456789012345678901234567890123

%N Semiprimes with consecutive (ascending) digits.

%C This is to semiprimes A001358 as A006055 is to primes A000040.

%e a(9) = 34567 because it is semiprime 13 * 2659, and (3,4,5,6,7) are consecutive ascending digits.

%Y Cf. A001358, A118697, A059043, A006055, A161760.

%K nonn,base,easy

%O 1,1

%A _Jonathan Vos Post_, Aug 12 2012

%E Corrected and extended by _R. J. Mathar_, Aug 13 2012

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Last modified April 6 15:41 EDT 2020. Contains 333276 sequences. (Running on oeis4.)