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A072475 Sum of next n composite numbers. 4
4, 14, 31, 63, 112, 176, 264, 385, 529, 712, 932, 1184, 1503, 1833, 2234, 2689, 3207, 3779, 4408, 5117, 5913, 6747, 7657, 8667, 9766, 10938, 12240, 13612, 15071, 16578, 18266, 20081, 22007, 23989, 26100, 28334, 30695, 33221, 35811, 38569, 41474 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

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

MATHEMATICA

Composite[n_Integer] := FixedPoint[n + PrimePi[ # ] + 1 &, n + PrimePi[n] + 1]; Table[ Sum[ Composite[i], {i, n(n - 1)/2 + 1, n(n + 1)/2}], {n, 1, 42}]

With[{terms=50}, cnos=With[{c=(terms(terms+1)(terms+2))/6}, Complement[ Range[5, c], Prime[Range[PrimePi[c]]]]]; Join[{4}, Total/@Table[Take[ cnos, {n (n+1)/2, (n+1) (n+2)/2-1}], {n, terms-1}]]] (* Harvey P. Dale, Oct 10 2011 *)

CROSSREFS

Cf. A072474, A007468, A006003.

Sequence in context: A117109 A140063 A051409 * A001740 A129395 A023539

Adjacent sequences:  A072472 A072473 A072474 * A072476 A072477 A072478

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Jun 20 2002

EXTENSIONS

More terms from Jim Nastos and Robert G. Wilson v, Jun 21 2002

STATUS

approved

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Last modified February 19 10:31 EST 2018. Contains 299330 sequences. (Running on oeis4.)