login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A152070 Squares which form nonzero squares when their reversal is subtracted from them. 0
6300100, 7502121, 16654561, 57942544, 74753316, 696379321, 1185424900, 2176315801, 16960113361, 21735899761, 44504965444, 52141439025, 95610824100, 105593152401, 189565322881, 213454164121, 293481144121, 527475375625 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

a(2) = 2739^2 = 7502121 => 7502121 - 1212057 = 6290064 = 2508^2

MATHEMATICA

nzsQ[n_]:=Module[{c=Sqrt[n-FromDigits[Reverse[IntegerDigits[n]]]]}, c!=0 && IntegerQ[c]]; Select[Range[750000]^2, nzsQ] (* Harvey P. Dale, Aug 03 2013 *)

PROG

(PARI) reverse(expr)=my(v=Vec(Str(expr)), n=length(v)); concat(vector(n, i, v[n-i+1])); lista(nn) = {for (n=1, nn, if (issquare(n), rn = eval(reverse(n)); if (n!= rn && issquare(n-rn), print1(n, ", "))); ); } \\ Michel Marcus, Jun 02 2013

CROSSREFS

Sequence in context: A138941 A251379 A203894 * A147531 A018895 A178135

Adjacent sequences:  A152067 A152068 A152069 * A152071 A152072 A152073

KEYWORD

nonn,base

AUTHOR

Gaurav Kumar, Jul 24 2009

EXTENSIONS

Definition clarified by Michel Marcus, Jun 02 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 1 10:33 EDT 2020. Contains 333159 sequences. (Running on oeis4.)