|
%I #15 Nov 21 2013 12:50:18
%S 5,2,5,5,5,10,5,12,15,10,19,18,12,10,7,9,10,2,28,5,21,5,45,36,16,22,
%T 17,5,42,10,48,69,28,5,10,20,7,21,24,13,10,36,5,23,16,48,40,10,24,23,
%U 61,10,46,129,20,28,10,139,36,52,5,10,108,18,17,5,169,24
%N Sum of the distinct prime divisors of prime(n) + prime(n+1).
%C a(n) = A008472(A001043(n)). [_Reinhard Zumkeller_, Jun 28 2011]
%H Reinhard Zumkeller, <a href="/A191583/b191583.txt">Table of n, a(n) for n = 1..10000</a>
%e a(6) = 10 because prime(6) + prime(7) = 13+17 = 30 = 2*3*5 and 2+3+5 = 10.
%p with(numtheory):for n from 1 to 100 do:x:=ithprime(n)+ithprime(n+1):y:=factorset(x):n1:=nops(y):s:=0:for k from 1 to n1 do:s:=s+y[k]:od:printf(`%d, `,s):od:
%t sdpd[n_]:=Total[Transpose[FactorInteger[n]][[1]]]; sdpd/@(Total/@ Partition[ Prime[Range[70]],2,1]) (* _Harvey P. Dale_, Mar 18 2012 *)
%o (PARI) vecsum(v)=sum(i=1,#v,v[i])
%o p=2;forprime(q=3,1e3,print1(vecsum(factor(p+q)[,1])", ");p=q)
%o \\ _Charles R Greathouse IV_, Jun 12 2011
%K nonn
%O 1,1
%A _Michel Lagneau_, Jun 07 2011
|
