A090346 Number of divisors of prime(n) + prime(n+1).

2, 4, 6, 6, 8, 8, 9, 8, 6, 12, 6, 8, 12, 12, 9, 10, 16, 8, 8, 15, 8, 10, 6, 8, 12, 12, 16, 16, 8, 20, 8, 6, 12, 18, 18, 12, 14, 16, 12, 12, 24, 12, 16, 16, 18, 8, 8, 18, 16, 16, 8, 24, 12, 6, 16, 12, 24, 6, 12, 12, 21, 24, 8, 20, 24, 20, 6, 18, 16, 16, 8, 12, 12, 10, 8, 6, 8, 16, 20, 18

Offset

1,1

Comments

Positions of odd terms (A064397): 7,15,20,61,152,190,293,377,492,558,789,919,942,1768,2343,2429,... [From Zak Seidov, Oct 12 2010]

Links

Table of n, a(n) for n=1..80.

Mathematica

d[i_] := DivisorSigma[0, Prime[i] + Prime[i + 1]]; Table[d[i], {i, 1, 100}]
DivisorSigma[0, #]&/@(Total/@Partition[Prime[Range[90]], 2, 1]) (* Harvey P. Dale, Mar 03 2023 *)

Crossrefs

Sequence in context: A161655 A092517 A128558 * A267460 A092989 A065558

Adjacent sequences: A090343 A090344 A090345 * A090347 A090348 A090349

Keyword

nonn

Author

Joseph L. Pe, Jan 28 2004

Status

approved