A248819 Numbers n such that the digits of antisigma(n) end in sigma(n).

79, 479, 2879, 4895, 26879, 79999, 644735, 799999, 2395488, 6399839, 8598719, 63652895, 144726608, 799999999, 935546879, 12640160863, 15282380799, 43687707904, 79999999999

Offset

1,1

Comments

All the primes of the form 8*10^k-1 for k>0 are terms (A056721). - Giovanni Resta, May 29 2016

Links

Table of n, a(n) for n=1..19.

Example

sigma(4895) = 6480 and antisigma of 4895 is (4895 * 4896) / 2 - sigma(4895) = 11982960 - 6480 = 11976480.

Maple

with(numtheory): P:=proc(q) local a, n;
for n from 1 to q do then a:=ilog10(sigma(n))+1;
if sigma(n)=((n*(n+1)/2-sigma(n)) mod 10^a) then print(n);
fi; od; end: P(10^9);

Crossrefs

Cf. A000230, A024816, A056721.

Sequence in context: A142556 A023315 A142618 * A141563 A107954 A098673

Adjacent sequences: A248816 A248817 A248818 * A248820 A248821 A248822

Keyword

nonn,more,base

Author

Paolo P. Lava, Oct 15 2014

Extensions

a(9)-a(19) from Giovanni Resta, May 29 2016

Status

approved