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

7, 12, 13, 28, 24, 39, 32, 42, 72, 54, 56, 96, 78, 93, 120, 168, 127, 96, 195, 140, 121, 132, 128, 156, 216, 192, 280, 152, 360, 176, 204, 288, 403, 372, 288, 378, 288, 324, 372, 546, 384, 508, 336, 468, 252, 256, 403, 560, 384, 420, 744, 504, 384, 588, 480

Offset: 1

Author

Joseph L. Pe, Jan 11 2003

Keywords

• easy
• nonn

Examples

			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.
		

Crossrefs

Cf. A000203, A024675.

Programs

Mathematica

Table[DivisorSigma[1, (Prime[i] + Prime[i + 1])/2], {i, 2, 101}]
DivisorSigma[1,Mean[#]]&/@Partition[Prime[Range[2,60]],2,1] (* Harvey P. Dale, Dec 07 2013 *)

Formula

a(n) = A000203(A024675(n)). - Omar E. Pol, Dec 08 2019