A277856 Numbers k such that the product of their digits divides both k and R(k), where R(k) is the digits reverse of k.

1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 111, 212, 216, 612, 1111, 1113, 1131, 1311, 2112, 3111, 4224, 4416, 6144, 11111, 11133, 11313, 11331, 11711, 13113, 13131, 13311, 21112, 21132, 21312, 23112, 23424, 31113, 31131, 31311, 33111, 42432, 42624, 111111, 211112, 211116

Offset

1,2

Comments

Subsequence of A007602.

Links

David A. Corneth, Table of n, a(n) for n = 1..1228 (first 200 terms from Paola P. Lava, terms < 10^13)

Maple

R:=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, n; for n from 1 to q do a:=convert(convert(n, base, 10), `*`);
if a>0 then if R(n) mod a=0 and n mod a=0 then print(n); fi; fi; od; end: P(10^12);

Mathematica

pddQ[n_]:=Module[{pd=Times@@IntegerDigits[n]}, pd!=0&&Mod[n, pd] == Mod[ IntegerReverse[n], pd]==0]; Select[Range[22*10^4], pddQ] (* Harvey P. Dale, Jan 07 2023 *)

Prog

(PARI) is(n) = { my(d = digits(n), vp = vecprod(d)); if(vp != 0 && n%vp == 0 && fromdigits(Vecrev(d))%vp == 0, return(1) ); 0 } \\ David A. Corneth, Mar 30 2021

Crossrefs

Cf. A004086, A007602.

Sequence in context: A083136 A369127 A229623 * A117057 A249516 A239090

Adjacent sequences: A277853 A277854 A277855 * A277857 A277858 A277859

Keyword

nonn,base,easy

Author

Paolo P. Lava, Nov 02 2016

Status

approved