A302651 Numbers that are the product of some fixed power of the digits of their ten's complement.

5, 8, 81, 2016, 2205

Offset

1,1

Comments

No other terms up to 10^40. - Giovanni Resta Apr 12 2018

No other terms up to 10^51 - Chai Wah Wu, Jun 06 2018

Links

Table of n, a(n) for n=1..5.

Example

(10 - 5) = 5 and 5^1 = 5;
(10 - 8) = 2 and 2^3 = 8;
(100 - 81) = 19 and 1^2 * 9^2 = 81;
(10000 - 2016) = 7984 and 7^1 * 9^1 * 8^1 * 4^1 = 2016;
(10000 - 2205) = 7795 and 7^1 * 7^1 * 9^1 * 5^1 = 2205;

Maple

with(numtheory): P:=proc(q) local a, b, i, j, k, n;
for n from 1 to q do a:=convert(10^(ilog10(n)+1)-n, base, 10);
b:=convert(a, `*`); j:=1; i:=0; while n>b do
if i=b then break; else i:=b; j:=j+1; b:=add(a[k]^j, k=1..nops(a)); fi; od;
if n=b then print(n); fi; od; end: P(10^9);

Crossrefs

Cf. A023052, A261433, A302649.

Sequence in context: A213239 A123819 A286076 * A260695 A153720 A372124

Adjacent sequences: A302648 A302649 A302650 * A302652 A302653 A302654

Keyword

nonn,base,more

Author

Paolo P. Lava, Apr 11 2018

Status

approved