

A078577


Sum of all prime factors of the average of nth twin prime pair.


3



4, 5, 7, 8, 10, 12, 12, 12, 22, 13, 28, 15, 15, 15, 19, 26, 16, 16, 52, 22, 36, 19, 17, 23, 37, 29, 19, 108, 112, 23, 19, 142, 33, 29, 22, 29, 52, 22, 67, 27, 20, 51, 79, 53, 43, 25, 31, 29, 37, 42, 76, 21, 146, 288, 53, 156, 27, 318, 37, 28, 48, 33, 352, 41, 26, 81, 32
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OFFSET

1,1


LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000


FORMULA

a(n) = A001414(A014574(n)).


EXAMPLE

12th twin prime pair = (A001359(12), A006512(12)) = (149,151), hence A014574(12) = 150 = 2*3*5*5, therefore a(12) = 2+3+5+5 = 15.


MATHEMATICA

midQ[n_] := PrimeQ[n1] && PrimeQ[n+1]; f[n_] := Plus @@ Times @@@ FactorInteger[n]; f /@ Select[Range[2500], midQ] (* Amiram Eldar, Nov 03 2019 *)


CROSSREFS

Cf. A001414, A014574, A078576, A078575, A078571.
Sequence in context: A202186 A247467 A032728 * A225387 A037259 A219115
Adjacent sequences: A078574 A078575 A078576 * A078578 A078579 A078580


KEYWORD

nonn


AUTHOR

Reinhard Zumkeller, Nov 29 2002


STATUS

approved



