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A075675 Sum of next n even interprimes. 3
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 16 21:55 EDT 2021. Contains 345080 sequences. (Running on oeis4.)