login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A159254 Numbers n with property that n^2 ends with 49. 3
7, 43, 57, 93, 107, 143, 157, 193, 207, 243, 257, 293, 307, 343, 357, 393, 407, 443, 457, 493, 507, 543, 557, 593, 607, 643, 657, 693, 707, 743, 757, 793, 807, 843, 857, 893, 907, 943, 957, 993, 1007, 1043, 1057, 1093, 1107, 1143, 1157, 1193, 1207, 1243, 1257 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

First 7 terms = 7th row in A111445.

LINKS

Table of n, a(n) for n=1..51.

Index entries for linear recurrences with constant coefficients, signature (1,1,-1).

FORMULA

a(1)=7, a(2)=43, a(n)=50+a(n-2).

From Colin Barker, Jul 04 2014: (Start)

a(n) = (11*(-1)^n+50*n-25)/2.

a(n) = a(n-1)+a(n-2)-a(n-3).

G.f.: x*(7*x^2+36*x+7) / ((x-1)^2*(x+1)). (End)

PROG

(PARI) select(n->n^2%100==49, vector(10^3, n, n)) \\ Colin Barker, Jul 04 2014

CROSSREFS

A111445 Triangle read by rows: row n contains the first n numbers whose squares end in n^2.

Sequence in context: A175159 A173828 A045800 * A062336 A085704 A243459

Adjacent sequences: A159251 A159252 A159253 * A159255 A159256 A159257

KEYWORD

base,nonn,easy

AUTHOR

Zak Seidov, Apr 07 2009

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 30 02:32 EST 2022. Contains 358431 sequences. (Running on oeis4.)