A075558 - OEIS

A075558

a(n) is the least composite number that has not yet appeared such that the n-th partial sum is a multiple of the n-th prime.

4, 8, 18, 12, 24, 25, 28, 14, 51, 48, 16, 85, 36, 104, 44, 66, 125, 146, 84, 56, 174, 96, 64, 185, 39, 165, 34, 68, 143, 72, 252, 203, 114, 38, 190, 189, 120, 446, 88, 132, 490, 410, 69, 50, 100, 249, 312, 535, 108, 54, 341, 168, 297, 290, 688, 186, 455, 335, 198, 413

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

MAPLE

s:= 0: Cands:= remove(isprime, [$4..1000]): nC:= nops(Cands):

R:= NULL: s:= 0: p:= 1:

for n from 1 do

p:= nextprime(p);

found:= false;

for i from 1 to nC do

if s + Cands[i] mod p = 0 then

R:= R, Cands[i];

s:= s + Cands[i];

Cands:= subsop(i=NULL, Cands);

nC:= nC-1;

found:= true;

break

od;

if not found then break fi

od:

CROSSREFS

Cf. A002808 (composite numbers).

Sequence in context: A145779 A252790 A144178 * A312824 A312825 A312826

Adjacent sequences: A075555 A075556 A075557 * A075559 A075560 A075561

KEYWORD

nonn,look

AUTHOR

Amarnath Murthy, Sep 24 2002

EXTENSIONS

More terms from Ray Chandler, Oct 25 2003

Name changed by Robert Israel, Dec 07 2024

STATUS

approved