OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
FORMULA
Note that when n is a palindrome, R(n)=n, so R(n) concat n = (10^d)n + n, where d is the number of digits of n, and R(n) is the reverse of n. Dividing by n, we obtain (R(n) concat n)/n = 10^d + 1. - Sam Alexander, Oct 21 2003; edited by Kevin Southwick, Jul 26 2015
MAPLE
f:= proc(n) local L, m, i, v;
L:= convert(n, base, 10);
m:= nops(L);
v:= add(10^(2*m-i)*L[i], i=1..m)/n+1;
if v::integer then v else NULL fi
end proc:
map(f, [$1..1000]); # Robert Israel, Jul 26 2015
MATHEMATICA
A083970 =
Select[ Range[ 250 ],
Divisible[
FromDigits[
Flatten[ { Reverse[ IntegerDigits[ # ] ], IntegerDigits[ # ] } ] ], # ] & ];
Table[ FromDigits[
Flatten[ { Reverse[ IntegerDigits[ tmp ] ], IntegerDigits[ tmp ] } ] ] /
tmp, {tmp, A083970} ]
(* Kevin Southwick, Jul 26 2015 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), May 21 2003
EXTENSIONS
Corrected and extended by Sam Alexander, Oct 21 2003
Name edited by Charles R Greathouse IV, Aug 05 2015
STATUS
approved