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A309542 Numbers k such that A001414(k^3+1) is divisible by k. 2
1, 2, 5, 7, 20, 24, 45, 54, 286, 1942, 30771000, 71149819, 106438598, 668274063 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(15) > 1.5*10^9. - Giovanni Resta, Aug 07 2019

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

5 is a member because the prime factorization of 5^3+1=126 is 2*3^2*7 and 2+3+3+7=15 is divisible by 5.

MAPLE

filter:= proc(n) local F, t;

  F:= ifactors(n^3+1)[2];

  add(t[1]*t[2], t=F) mod n = 0

end proc:

select(f, [$1..10000]);

CROSSREFS

Cf. A001414, A309534, A309544.

Sequence in context: A096146 A041583 A143915 * A327322 A160820 A158357

Adjacent sequences:  A309539 A309540 A309541 * A309543 A309544 A309545

KEYWORD

nonn,more

AUTHOR

J. M. Bergot and Robert Israel, Aug 06 2019

EXTENSIONS

a(11)-a(14) from Giovanni Resta, Aug 07 2019

STATUS

approved

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Last modified January 24 13:24 EST 2020. Contains 331193 sequences. (Running on oeis4.)