A237877 Numbers n such that n | A067439(n).

1, 2, 9, 11, 17, 48, 57, 427, 533, 1661, 2161, 4441, 5428, 41628, 171441, 411735, 555716, 1278525, 4292829, 5174373, 8758407, 680133057

Offset

1,2

Comments

a(19) > 3000000. - Giovanni Resta, Feb 17 2014

a(23) > 4 * 10^9. - Hiroaki Yamanouchi, Sep 27 2015

Links

Table of n, a(n) for n=1..22.

Example

48 is coprime to 1, 5, 7, 11, 13, 17, 19, 23, 25, 29, 31, 35, 37, 41, 43, 47. When 48 is divided by these numbers the remainders are 0, 3, 6, 4, 9, 14, 10, 2, 23, 19, 17, 13, 11, 7, 5, 1. Their sum is 144 and 144 / 48 = 3.

Maple

with(numtheory); P:=proc(q) local i, n, t; for n from 1 to q do t:=0;
for i from 2 to n-1 do if gcd(i, n)=1 then t:=t+(n mod i); fi; od;
if type(t/n, integer) then print(n); fi; od; end: P(10^6);

Prog

(PARI) is(n)=sum(i=1, n-1, if(gcd(n, i)==1, n%i))%n==0 \\ Charles R Greathouse IV, Nov 06 2014

Crossrefs

Cf. A067439.

Sequence in context: A138759 A345925 A098934 * A043307 A049343 A131140

Adjacent sequences: A237874 A237875 A237876 * A237878 A237879 A237880

Keyword

nonn,more

Author

Paolo P. Lava, Feb 14 2014

Extensions

a(14) from Michel Marcus, Feb 17 2014

a(15)-a(18) from Giovanni Resta, Feb 17 2014

a(19)-a(22) from Hiroaki Yamanouchi, Sep 27 2015

Status

approved