A376103 a(1) = 5; for n > 1, a(n) is the smallest palindromic prime containing exactly 2 more digits on each end than a(n-1), with a(n-1) as the central substring.

5, 10501, 111050111, 1211105011121, 39121110501112193, 393912111050111219393, 7239391211105011121939327, 79723939121110501112193932797, 157972393912111050111219393279751, 7415797239391211105011121939327975147

Offset: 1

Author

Shyam Sunder Gupta, Sep 10 2024

Keywords

• nonn
• base
• fini
• full

Comments

This is a finite sequence since at a(10) there is no way to add 2 more digits and reach a palindromic prime.

Examples

			As a triangle:
          5
        10501
      111050111
    1211105011121
  39121110501112193
		

Crossrefs

Cf. A047076, A053600, A375690, A082563.