A241177 Numbers n such that there are exactly two numbers m with m + (some digit of m) = n.

10, 12, 24, 32, 36, 48, 54, 60, 72, 76, 84, 96, 98, 109, 112, 123, 125, 127, 129, 131, 132, 133, 135, 137, 139, 141, 145, 147, 149, 151, 153, 155, 157, 159, 161, 163, 167, 169, 171, 172, 173, 175, 177, 179, 181, 183, 185, 189, 191, 193, 195, 197, 199, 201, 209, 211, 213, 215, 217, 219, 224, 233, 235, 237, 239, 241, 245

Offset: 1

Author

N. J. A. Sloane, Apr 23 2014

Keywords

• nonn
• base

Comments

The numbers 12, 112, 1112, ..., 111...112, ... are terms of the sequence. - Marius A. Burtea, Feb 18 2020

Examples

			12 = 6 + 6 = 11 + 1.
32 = 26 + 6 = 31 + 1.
112 = 106 + 6 = 111 + 1.
		

References

• Eric Angelini, Posting to Sequence Fans Mailing List, Apr 20 2014.

Links

• David A. Corneth, Table of n, a(n) for n = 1..13111 (Terms <= 10^6)

Crossrefs

Related sequences: A241173, A241174, A241175, A241176, A241177, A241178, A241179, A241180, A241181, A241182, A241183.

Programs

Magma

f:=func; [k:k in [1..250]| #[m:m in [1..k]| f(k,m)] eq 2]; // Marius A. Burtea, Feb 18 2020

Maple

M:=2000;
M2:=M+10;
A:=Array[0..M2];
for n from 0 to M2 do A[n]:=0; od:
for n from 0 to M do
t1:=convert(n,base,10);
t2:=convert(t1,set); t3:=convert(t2,list);
for i from 1 to nops(t3) do A[n+t3[i]]:= A[n+t3[i]]+1; od:
                  od:
ans:=[];
for n from 0 to M do if A[n]=2 then ans:=[op(ans),n]; fi; od:
[seq(ans[i],i=1..nops(ans))];

Mathematica

A241177[n_] := Module[{m, c = 0},
   Do[c = c + Count[m + Union[IntegerDigits[m]], n], {m, 0, n}]; c];
Select[Range[0, 245], A241177[#] == 2 &] (* Robert Price, Mar 20 2019 *)

PARI

upto(n) = {my(v = vector(n + 9)); for(i = 1, n, d = Set(digits(i)); for(j = 1, #d, v[i + d[j]]++ ) ); for(i = n + 1, n + 9, v[i] = 0); select(x -> x == 2, v, 1) } \\ David A. Corneth, Mar 20 2019