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 A078577 Sum of all prime factors of the average of n-th 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 (list; graph; refs; listen; history; text; internal format)
 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[n-1] && 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

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Last modified January 26 07:24 EST 2022. Contains 350573 sequences. (Running on oeis4.)