A254008 Numbers that divide the sum of the reverse of their divisors (A069192).

1, 6, 15, 37, 87, 397, 435, 639, 1086, 2574, 8997, 10986, 26994, 101918, 161406, 207321, 793170, 834657, 890827, 1976355, 3224625, 7591023, 8999997, 9970098, 11052598, 17930619, 18368601, 21739023, 38014197, 89999997, 109999986, 116141652, 177765554, 201264120

Offset

1,2

Links

Lars Blomberg, Table of n, a(n) for n = 1..41

Example

Divisors of 8997 are 1, 3, 2999, 8997 and the sum of their reverse is 1 + 3 + 9992 + 7998 = 17994. Finally, 17994 / 8997 = 2.

Maple

with(numtheory):
T:=proc(w) local x, y, z; x:=w; y:=0;
for z from 1 to ilog10(x)+1 do y:=10*y+(x mod 10); x:=trunc(x/10); od; y; end:
P:=proc(q) local a, b, k; global n;
for n from 1 to q do a:=sort([op(divisors(n))]); b:=add(T(a[k]), k=1..nops(a));
if type(b/n, integer) then print(n); fi; od; end: P(10^9);

Prog

(Magma) [n: n in [1..10^6] | &+[Seqint(Reverse(Intseq(d))): d in Divisors(n)] mod n eq 0]; // Bruno Berselli, Jan 22 2015

Crossrefs

Cf. A069192, A254009.

Sequence in context: A221905 A083011 A299267 * A277089 A271545 A272258

Adjacent sequences: A254005 A254006 A254007 * A254009 A254010 A254011

Keyword

nonn,base

Author

Paolo P. Lava, Jan 22 2015

Extensions

a(19)-a(33) from Lars Blomberg, Feb 27 2015

Status

approved