A250067 Numbers n such that n = Rev(sigma*(n)), where sigma*(n) is the sum of the anti-divisors of n and Rev(n) is the reverse of n.

5, 8, 64, 614, 47678, 4442395

Offset

1,1

Links

Table of n, a(n) for n=1..6.

Example

Anti-divisors of 5 are 2, 3 and 2 + 3 = 5 = Rev(5).
Anti-divisors of 614 are 3, 4, 409 and 3 + 4 + 409 = 416 = Rev(614).

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 j, k, n; for n from 1 to q do
k:=0; j:=n; while j mod 2 <> 1 do k:=k+1; j:=j/2; od;
if sigma(2*n+1)+sigma(2*n-1)+sigma(n/2^k)*2^(k+1)-6*n-2=T(n);
then print(n); fi; od; end: P(10^9);

Crossrefs

Cf. A000203, A066417, A178029, A248787.

Sequence in context: A068478 A342195 A132050 * A213239 A123819 A286076

Adjacent sequences: A250064 A250065 A250066 * A250068 A250069 A250070

Keyword

nonn,base,more

Author

Paolo P. Lava, Nov 11 2014

Extensions

a(6) from Chai Wah Wu, Dec 06 2014

Status

approved