login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A159815 Numbers n with property that n^2 starts and ends with 49. 0
7, 707, 7007, 7043, 7057, 22143, 22157, 22193, 22207, 22243, 22257, 22293, 22307, 22343, 22357, 70007, 70043, 70057, 70093, 70107, 70143, 70157, 70193, 70207, 70243, 70257, 70293, 70307, 70343, 70357, 70393, 70407, 70443, 70457, 70493 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Most first differences are alternatively 14 and 36.

EXAMPLE

{7,707,7007,7043,7057,22143,22157}^2={49,499849,49098049,49603849,49801249,490312449,490932649}.

MATHEMATICA

s7={}; Do[If[Take[IntegerDigits[n^2], 2]=={4, 9}&&PowerMod[n, 2, 100]==49, AppendTo[s7, n]], {n, 7, 300000}]; s7

CROSSREFS

A159775 Numbers n with property that n^2 starts and ends with 81. A159754 Numbers n with property that n^2 ends with 81. A159254 Numbers n with property that n^2 ends with 49. A111445 n-th row contains first n numbers whose squares end in n^2.

Sequence in context: A174855 A186160 A129291 * A070746 A068004 A098110

Adjacent sequences:  A159812 A159813 A159814 * A159816 A159817 A159818

KEYWORD

base,nonn

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Apr 22 2009

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 22:48 EST 2012. Contains 206085 sequences.