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A078835 Sum of the divisors of the average of consecutive odd primes. 0

%I #9 Dec 08 2019 12:28:45

%S 7,12,13,28,24,39,32,42,72,54,56,96,78,93,120,168,127,96,195,140,121,

%T 132,128,156,216,192,280,152,360,176,204,288,403,372,288,378,288,324,

%U 372,546,384,508,336,468,252,256,403,560,384,420,744,504,384,588,480

%N Sum of the divisors of the average of consecutive odd primes.

%F a(n) = A000203(A024675(n)). - _Omar E. Pol_, Dec 08 2019

%e The first pair of consecutive odd primes is 3,5, with average = 4 and sigma(4) = 7. Hence a(1) = 7. The second pair of consecutive odd primes is 5,7, with average = 6 and sigma(6) = 12, so a(2) = 12.

%t Table[DivisorSigma[1, (Prime[i] + Prime[i + 1])/2], {i, 2, 101}]

%t DivisorSigma[1,Mean[#]]&/@Partition[Prime[Range[2,60]],2,1] (* _Harvey P. Dale_, Dec 07 2013 *)

%Y Cf. A000203, A024675.

%K easy,nonn

%O 1,1

%A _Joseph L. Pe_, Jan 11 2003

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Last modified April 23 08:33 EDT 2024. Contains 371905 sequences. (Running on oeis4.)