A261022 Numbers that are the sum of 2 successive primes and also twice the sum of 2 lesser successive primes.

24, 36, 60, 84, 120, 240, 276, 288, 372, 396, 480, 576, 600, 924, 1064, 1200, 1236, 1392, 1620, 1656, 1764, 1848, 2088, 2240, 2280, 2440, 2460, 2580, 2640, 2856, 2964, 3240, 3264, 3336, 3444, 3756, 4044, 4176, 4224, 4828, 4860, 5280, 5376, 5940, 6300, 6480, 6660

Offset

1,1

Comments

Terms in A001043 that are twice some lesser term. Numbers m such that both m and m/2 are terms in A001043.

Links

Zak Seidov and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 1000 terms from Seidov)

Example

a(1)=24 because 24=A001043(5)=2*A001043(3), or 11+13=2*(5+7),
a(10)=396 because 396=A001043(45)=2*A001043(25), or 197+199=2*(97+101),
a(100)=16020 because 16020=A001043(1008)=2*A001043(552), or 8009+8011=2*(4003+4007),
a(1000)=324804 because 324804=A001043(14877)=2*A001043(7948), or 162391+162413=2*(81199+81203).

Mathematica

Module[{pr=Prime[Range[500]], p1, p2}, p1=Total/@Partition[pr, 2, 1]; p2=2p1; Intersection[p1, p2]] (* Harvey P. Dale, May 07 2019 *)

Prog

(PARI) p=3; forprime(q=5, 1e4, t=p+q; if(t%4==0 && nextprime(t/4+1)+precprime(t/4) == t/2, print1(t", ")); p=q) \\ Charles R Greathouse IV, Aug 07 2015

Crossrefs

Cf. A001043.

Sequence in context: A038530 A262428 A281925 * A179152 A193069 A347422

Adjacent sequences: A261019 A261020 A261021 * A261023 A261024 A261025

Keyword

nonn

Author

Zak Seidov, Aug 07 2015

Status

approved