A255005 a(n) = the digit sum of prime(n) + the digit product of prime(n).

4, 6, 10, 14, 3, 7, 15, 19, 11, 29, 7, 31, 9, 19, 39, 23, 59, 13, 55, 15, 31, 79, 35, 89, 79, 2, 4, 8, 10, 8, 24, 8, 32, 40, 50, 12, 48, 28, 56, 32, 80, 18, 20, 40, 80, 100, 6, 19, 39, 49, 26, 68, 15, 18, 84, 47, 125, 24, 114, 27, 61, 68, 10, 8, 16, 32, 16

Offset: 1

Author

Vincenzo Librandi, Feb 12 2015

Keywords

• nonn
• base

Examples

			Prime(5)=11 and (1*1) + (1+1) = 3 so a(5) = 3.
Prime(10)=29 and (2*9) + (2+9) = 29 so a(10) = 29.
		

Links

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

Crossrefs

Subsequence of A061762.

Cf. A007605, A053666.

Programs

Magma

[&*Intseq(NthPrime(n))+&+Intseq(NthPrime(n)): n in [1..80]];

Mathematica

Table[Plus @@ IntegerDigits[Prime[n]] + Times @@ IntegerDigits[Prime[n]], {n, 80}] (* Bruno Berselli, Feb 12 2015 *)
dsdp[n_]:=Module[{idpn=IntegerDigits[Prime[n]]},Total[idpn]+Times@@idpn]; dsdp/@Range[70] (* Harvey P. Dale, Mar 05 2017 *)

Formula

a(n) = A007605(n) + A053666(n).