A088135 Sum of first and last digits of n-th prime.

4, 6, 10, 14, 2, 4, 8, 10, 5, 11, 4, 10, 5, 7, 11, 8, 14, 7, 13, 8, 10, 16, 11, 17, 16, 2, 4, 8, 10, 4, 8, 2, 8, 10, 10, 2, 8, 4, 8, 4, 10, 2, 2, 4, 8, 10, 3, 5, 9, 11, 5, 11, 3, 3, 9, 5, 11, 3, 9, 3, 5, 5, 10, 4, 6, 10, 4, 10, 10, 12, 6, 12, 10, 6, 12, 6, 12, 10, 5, 13, 13, 5, 5, 7, 13, 7, 13

Offset: 1

Author

Zak Seidov, Sep 20 2003

Keywords

• easy
• nonn
• base

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A046704, A007953, A088133, A088134, A088136.

Programs

Mathematica

sfl[p_]:=Module[{idn=IntegerDigits[p]},idn[[1]]+idn[[-1]]]; sfl/@Prime[Range[90]] (* Harvey P. Dale, Jan 31 2023 *)