A096768 Numbers n of the form k + reverse(k) for two or more values of k.

22, 33, 44, 55, 66, 77, 88, 99, 110, 121, 132, 143, 154, 165, 176, 187, 202, 222, 242, 262, 282, 302, 303, 322, 323, 342, 343, 362, 363, 382, 383, 403, 404, 423, 424, 443, 444, 463, 464, 483, 484, 504, 505, 524, 525, 544, 545, 564, 565, 584, 585, 605, 606

Offset: 1

Author

Chuck Seggelin (seqfan(AT)plastereddragon.com), Jul 08 2004

Keywords

• base
• easy
• nonn

Examples

			22 belongs to the sequence since 11 + 11 = 22 and 20 + 2 = 22 (k = {11, 20}); 33 belongs to the sequence since 12 + 21 = 33, 21 + 12 = 33 and 30 + 3 = 33 (k = {12, 21, 30}).
		

Links

• N. J. A. Sloane, Table of n, a(n) for n = 1..2106
• Index entries for sequences related to Reverse and Add!

Crossrefs

Cf. A067030, A072040 (exactly two values of k).

Programs

Maple

reverse:= proc (d) local n,m; m:=0;n:=d; while n>0 do m:=m*10+(n mod 10); n:=(n-(n mod 10))/10; od; m; end; P:={};P2:={};for i to 5000 do; if i>0 then; r:=i+reverse(i); rat:={r}; if P intersect rat = {} then P:=P union rat else P2:=P2 union rat fi; fi; od; P2;
# Maple program from N. J. A. Sloane, Mar 07 2016. Assumes digrev (from the "transforms" file) is available:
M:=1000; b := Array(1..M,0);
for n from 1 to M do
t1:=n+digrev(n);
if t1 <= M then b[t1]:=b[t1]+1; fi;
od:
ans:=[];
for n from 1 to M do
if b[n]>=2 then ans:=[op(ans),n]; fi; od:
ans;

Mathematica

M = 10^3; digrev[n_] := IntegerDigits[n] // Reverse // FromDigits; Clear[b]; b[A096768%20=%20Reap%5BFor%5Bn%20=%201,%20n%20%3C=%20M,%20n++,%20If%5Bb%5Bn%5D%20%3E=%202,%20Sow%5Bn%5D%5D%5D%5D%5B%5B2,%201%5D%5D%20(*%20_Jean-Fran%C3%A7ois%20Alcover">] = 0; For[n = 1, n <= M, n++, t1 = n + digrev[n]; If[t1 <= M, b[t1] = b[t1] + 1]]; A096768 = Reap[For[n = 1, n <= M, n++, If[b[n] >= 2, Sow[n]]]][[2, 1]] (* _Jean-François Alcover, Oct 01 2016, after N. J. A. Sloane's Maple code *)