cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-3 of 3 results.

A122986 Squares mod 1000.

Original entry on oeis.org

0, 1, 4, 9, 16, 24, 25, 36, 41, 44, 49, 56, 64, 76, 81, 84, 89, 96, 100, 104, 116, 121, 124, 129, 136, 144, 156, 161, 164, 169, 176, 184, 196, 201, 204, 209, 216, 224, 225, 236, 241, 244, 249, 256, 264, 276, 281, 284, 289, 296, 304, 316, 321, 324, 329, 336, 344
Offset: 1

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Author

Sergio Pimentel, Sep 22 2006

Keywords

Comments

Possible last three digits of n^2 (leading zeros omitted).
Range of A174452; A010461 is a subset; and also all squares less than 1000 belong to this sequence; the sequence is finite with A000993(3)=159 terms: a(159)=996 is the last term.

Examples

			The last three digits of n^2 can be 000, 001, 236, 241, 996, etc. but not 002, 003, 237, 238, etc.
		

Crossrefs

Programs

  • Magma
    [n: n in [0..999] | IsSquare(R! n) where R:= ResidueClassRing(1000)]; // Vincenzo Librandi, Dec 29 2019
  • Maple
    s:={}: for n from 0 to 999 do s:=s union {n^2 mod 1000}: od: op(s); # Nathaniel Johnston, Jun 22 2011
  • Mathematica
    Union[PowerMod[Range[1000], 2, 1000]] (* Vincenzo Librandi, Dec 29 2019 *)

Extensions

More terms and additional comments from Reinhard Zumkeller, Mar 21 2010
Edited by N. J. A. Sloane, Apr 10 2010

A119162 Triangular numbers composed of digits {2,4,8}.

Original entry on oeis.org

28, 48828, 828828, 842288428828, 24884484228828, 28284882828828, 2842448222228428828
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(8) > 10^40. - Tyler Busby, Mar 29 2023

Crossrefs

Cf. A000217, A027678, A119163. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119163(n)). - Tyler Busby, Mar 29 2023

A027679 When squared gives number composed of digits {2,4,8} with each of these digits appearing at least once.

Original entry on oeis.org

168, 478, 2878, 210912978, 15647628653832, 1511583350076478, 6548620039541478, 669644852476481662, 20597146608802018338, 53710727465081333454522, 2069416058768323727702022, 149140498954591218312271662, 20598117118436403877526792022
Offset: 1

Views

Author

Keywords

Crossrefs

Cf. A027678.

Extensions

One more term from Jon E. Schoenfield, Sep 04 2006
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), May 19 2007
Title improved by Sean A. Irvine, Nov 24 2019
a(12)-a(13) from Zhao Hui Du, Mar 09 2024
Showing 1-3 of 3 results.