A176915 Average of n-th twin prime pair minus total number of prime factors of average of n-th twin prime pair.

2, 4, 9, 15, 27, 39, 56, 67, 99, 103, 135, 146, 175, 185, 194, 224, 234, 265, 279, 307, 344, 415, 425, 458, 518, 566, 594, 615, 639, 655, 804, 819, 823, 854, 877, 1015, 1027, 1045, 1058, 1087, 1143, 1226, 1274, 1286, 1298, 1314, 1423, 1447, 1478, 1482, 1603

Offset

1,1

Comments

Prime factors are counted with multiplicity. - Harvey P. Dale, Aug 19 2011

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

a(n) = A014574(n)-A078571(n).

a(n) = A069345(A014574(n)). - Jason Yuen, Sep 01 2025

Maple

TP:= select(t -> isprime(t) and isprime(t+2), [3, seq(i, i=5..2000, 6)]):
map(t -> t+1 - numtheory:-bigomega(t+1), P1); # Robert Israel, Dec 31 2024

Mathematica

f[n_]:=Module[{mn=Mean[n]}, mn-PrimeOmega[mn]]; f/@Select[Partition[ Prime[ Range[300]], 2, 1], Last[#]-First[#]==2&] (* Harvey P. Dale, Aug 19 2011 *)

Crossrefs

Cf. A014574, A069345, A078571.

Sequence in context: A072846 A157254 A080004 * A060742 A060737 A266647

Adjacent sequences: A176912 A176913 A176914 * A176916 A176917 A176918

Keyword

nonn,easy

Author

Juri-Stepan Gerasimov, Apr 28 2010

Extensions

Formula index, a(8), a(15) and a(23) corrected by R. J. Mathar, May 01 2010

Status

approved