A249630 Sums of the composite numbers placed between two consecutive prime numbers (A054265), sorted in increasing order.

0, 4, 6, 12, 18, 27, 30, 42, 45, 60, 63, 72, 102, 108, 117, 130, 135, 138, 150, 170, 180, 192, 198, 207, 228, 240, 243, 250, 270, 280, 282, 297, 312, 315, 320, 333, 348, 380, 387, 420, 430, 432, 462, 495, 522, 570, 585, 600, 618, 642, 651, 660, 670, 675, 693

Offset

1,2

Comments

The first number that occurs more than once is 2592 = a(143) = a(144). - Robert Israel, Nov 11 2014

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Maple

N:= 1000: # to get all terms <= N
Primes:= select(isprime, [2, seq(2*i+1, i=1..floor(N/2))]):
B:= [seq((Primes[i+1]+Primes[i])*(Primes[i+1]-Primes[i]-1)/2, i=1..nops(Primes)-1)]:
sort(select(`<=`, B, N)); # Robert Israel, Nov 11 2014

Mathematica

With[{nn=60}, Take[Sort[Total[Range[#[[1]]+1, #[[2]]-1]]&/@Partition[ Prime[ Range[3*nn]], 2, 1]], nn]] (* Harvey P. Dale, Sep 25 2015 *)

Prog

(PARI) lista() = {vitp = readvec("c:/gp/bfiles/b029707.txt"); for (k=1, #vitp, v = []; for (n=1, k, vn = vitp[n]; for (j=1, vn, newv = (prime(j+1)+prime(j))*(prime(j+1)-prime(j)-1)/2; if (! vecsearch(v, newv), v = vecsort(concat(v, newv))); ); ); /* to see intermediate results for (i=1, #v, if (v[i] <= newv, print1(v[i], ", ")); ); print(); */); v; } \\ Michel Marcus, Nov 11 2014

Crossrefs

Cf. A054265.

Sequence in context: A296507 A072568 A154965 * A109290 A130441 A074998

Adjacent sequences: A249627 A249628 A249629 * A249631 A249632 A249633

Keyword

nonn

Author

Yves Debeuret, Nov 02 2014

Extensions

More terms from Michel Marcus, Nov 11 2014

Status

approved