A194427 Indices k of twin prime averages A014574 which are two thirds of another twin prime average.

1, 3, 8, 13, 21, 47, 65, 99, 143, 209, 214, 227, 233, 234, 244, 260, 277, 283, 297, 328, 353, 399, 409, 431, 451, 509, 516, 533, 543, 671, 675, 677, 701, 737, 741, 748, 767, 786, 795, 804, 854, 856, 890, 937, 981, 986, 992, 994, 1014, 1080, 1098, 1129, 1130, 1160, 1200, 1213, 1222, 1227, 1258

Offset: 1

Author

Juri-Stepan Gerasimov, Dec 02 2011

Keywords

• nonn
• changed

Examples

			3 is in the sequence because A014574(3)=12 is two thirds of 18 and 18 is also a twin prime average.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..2500

Crossrefs

Cf. A014574.

Programs

Maple

TPA:= 4: count:= 1:
for p from 5 by 6 while count < 2000 do
  if isprime(p) and isprime(p+2) then count:= count+1; TPA:= TPA, p+1;  fi
od:
TPA:= [TPA]:
TPAS:= convert(TPA,set):
T3:= map(`*`,TPAS,2/3) intersect TPAS:
V:= Vector(nops(T3), proc(i) local k; member(T3[i],TPA,'k'); k end proc):
convert(V,list); # Robert Israel, Aug 26 2025