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A255005
a(n) = the digit sum of prime(n) + the digit product of prime(n).
1
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
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.
Sequence in context: A141740 A088135 A302660 * A376379 A137699 A144592
KEYWORD
nonn,base
AUTHOR
Vincenzo Librandi, Feb 12 2015
STATUS
approved