a(n) is the number from which if odd-positioned digits are deleted then one gets the concatenation of first n composite numbers, while if even-positioned digits are deleted then one gets reverse concatenation of first n composite numbers. Position of least significant digit is considered to be 1.

A078279

a(n) is the number from which if odd-positioned digits are deleted then one gets the concatenation of first n composite numbers, while if even-positioned digits are deleted then one gets reverse concatenation of first n composite numbers. Position of least significant digit is considered to be 1.

Terms

    a(0) =44a(1) =4664a(2) =486684a(3) =49688694a(4) =416089981604

External references