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

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A045859 Numbers k such that k^2 has initial digit '5'. 1
23, 24, 71, 72, 73, 74, 75, 76, 77, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 708, 709, 710, 711, 712, 713, 714, 715, 716, 717, 718, 719, 720, 721, 722, 723, 724, 725, 726, 727, 728, 729, 730 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A000030(A000290(a(n))) = 5. [Reinhard Zumkeller, Mar 07 2010]

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..10000

MATHEMATICA

Rest[Table[If[First[IntegerDigits[n^2]] == 5, n, 0], {n, 1, 2500}]// Union] (* José María Grau Ribas, Feb 15 2010 *)

PROG

(PARI) isok(n) = digits(n^2)[1] == 5; \\ Michel Marcus, Dec 13 2017

CROSSREFS

Sequence in context: A042062 A042060 A042058 * A042078 A042080 A042076

Adjacent sequences:  A045856 A045857 A045858 * A045860 A045861 A045862

KEYWORD

nonn,base,changed

AUTHOR

Jeff Burch

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 16 18:57 EST 2017. Contains 296092 sequences.