Semiprimes with digits in descending order that differ exactly by 1.

A215478

Semiprimes with digits in descending order that differ exactly by 1.

Terms

    a(0) =4a(1) =6a(2) =9a(3) =10a(4) =21a(5) =65a(6) =87a(7) =321a(8) =543a(9) =4321a(10) =8765a(11) =98765a(12) =654321a(13) =876543a(14) =7654321

External references