A075675 Sum of next n even interprimes.

4, 18, 74, 182, 358, 746, 1176, 1854, 2650, 3870, 5696, 7358, 9818, 13052, 16134, 19742, 24192, 30048, 36306, 42932, 50954, 59904, 70210, 82646, 93446, 105640, 117558, 131950, 148108, 165772

Offset

1,1

Comments

Sum of next n primes in A007468. Sum of next n integer interprimes in A075673. Sum of next n odd interprimes in A075674.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(1) = (3+5)/2 = 4; a(2) = (5+7)/2+(11+13)/2 = 6 + 12 = 18.

Mathematica

ev=Select[Table[(Prime[i]+Prime[i+1])/2, {i, 2, 2000}], EvenQ]; (* sum of next n even interprimes*) i1 := n(n-1)/2+1; i2 := n(n-1)/2+n; A075675=Table[Sum[ev[[i]], {i, i1, i2}], {n, 30}]
Module[{nn=1000, ip, len}, ip=Select[Mean/@Partition[Prime[Range[nn]], 2, 1], EvenQ]; len=Length[ip]; Total/@TakeList[ip, Range[(Sqrt[1+8*len]-1)/2]]] (* Requires Mathematica version 11 or later *) (* Harvey P. Dale, Jun 30 2020 *)

Crossrefs

Cf. A007468, A075673, A075674, A075675.

Sequence in context: A027905 A037497 A202358 * A047034 A266753 A307323

Adjacent sequences: A075672 A075673 A075674 * A075676 A075677 A075678

Keyword

nonn

Author

Zak Seidov, Sep 24 2002

Status

approved