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

1,1

Links

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

Formula

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

Example

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.

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 *)

Prog

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

Crossrefs

Subsequence of A061762.

Cf. A007605, A053666.

Sequence in context: A141740 A088135 A302660 * A376379 A137699 A144592

Adjacent sequences: A255002 A255003 A255004 * A255006 A255007 A255008

Keyword

nonn,base

Author

Vincenzo Librandi, Feb 12 2015

Status

approved