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A330579 Numbers k such that the k-th composite number divides the sum of the first k composite numbers. 2
1, 4, 493, 1565, 6210, 26375, 64019, 289862, 870828, 1244485, 3313113, 4300012, 7946206, 1447234860, 4147639664, 7190149312, 23828369695, 39710847388, 494027033160, 982853084580, 1095174951021, 1141650682059, 1522735118076, 1642938906044 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence corresponds to the positions of zeros in A330578.

LINKS

Table of n, a(n) for n=1..24.

EXAMPLE

The first 4 composite numbers are: 4, 6, 8 and 9.

As 4 + 6 + 8 + 9 = 3*9, 4 belongs to the sequence.

PROG

(PARI) s=0; k=0; forcomposite (c=4, oo, k++; s+=c; if (s%c==0, print1 (k", ")))

CROSSREFS

Cf. A024011 (prime variant), A330578, A330580.

Sequence in context: A069500 A053953 A024058 * A221554 A210310 A324155

Adjacent sequences:  A330576 A330577 A330578 * A330580 A330581 A330582

KEYWORD

nonn,more

AUTHOR

Rémy Sigrist, Dec 18 2019

EXTENSIONS

a(15)-a(24) from Giovanni Resta, Dec 20 2019

STATUS

approved

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Last modified April 6 14:08 EDT 2020. Contains 333276 sequences. (Running on oeis4.)