a(1)=88; for n>=1, a(n+1) is the smallest palindromic 4-almost prime with a(n) as a central substring.

A248047

a(1)=88; for n>=1, a(n+1) is the smallest palindromic 4-almost prime with a(n) as a central substring.

Terms

    a(0) =88a(1) =1881a(2) =218812a(3) =12188121a(4) =1121881211a(5) =111218812111

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