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 1-4 of 4 results.

A030175 When squared gives number composed of digits {1,2,3}.

Original entry on oeis.org

1, 11, 111, 36361, 363639, 461761, 3636361, 34815389, 362397739, 176412364139, 57637950363639, 3497458093147239, 56843832676142723489, 557963558954625926861
Offset: 1

Views

Author

Patrick De Geest

Keywords

Links

Crossrefs

Cf. A030174; A000290.
Cf. A006716 = A027675^2, A030176 = A030177^2, A058411^2 = A058412, ..., A058473^2 = A058474.
Cf. A136808, A136809, ..., A137147: n and n^2 have digits {...}.
Cf. A277959^2 = A277946 and A277960^2 = A277947: squares whose largest digit is 2 resp. 3.

Programs

  • Mathematica
    Do[ If[ Union[ Join[{1, 2, 3}, IntegerDigits[n^2] ] ] == {1, 2, 3}, Print[n] ], {n, 0, 10^9}]
  • PARI
    lista(nn) = for(n=1, nn, if(setminus(vecsort(digits(n^2), , 8), [1, 2, 3])==[], print1(n, ", "))) \\ Iain Fox, Nov 16 2017

Formula

a(n)^2 = A030174(n). - M. F. Hasler, Nov 16 2017

Extensions

More terms from Patrick De Geest, Mar 01 2000
More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 14 2005
Offset corrected by Iain Fox, Nov 16 2017

A030177 When squared gives number composed of digits {4,5,6}.

Original entry on oeis.org

2, 8, 216, 238, 258, 738, 6742, 25408, 80408, 2377908, 80278612, 667567716, 6756141388, 6823243112, 23802219742, 81648365908, 2136952377908, 80401900255258, 258159749875238, 25425667278648884, 237605691124298293112, 75269219840819770294592, 675754811056988742949784
Offset: 1

Views

Author

Patrick De Geest

Keywords

Links

Crossrefs

Cf. A030176.

Extensions

More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 14 2005
Two more terms from Jon E. Schoenfield, Sep 04 2006
More terms from Mishima's webpage added by Max Alekseyev, May 18 2009
Offset corrected by Zhao Hui Du, Feb 29 2024

A119202 Triangular numbers composed of digits {4,5,6}.

Original entry on oeis.org

6, 45, 55, 66, 465, 666, 4465, 4656, 5565, 6555, 46665, 544446, 4465566, 5456556, 5656566, 64564566, 4565545455565, 4664644554466, 56466665456545, 555445466565465, 555445666545666, 555665666566566, 4446456564566646, 6666664664655666, 46566644555566656
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Links

Crossrefs

Cf. A000217, A030176, A119203. See A119033 for a table of cross-references.

Programs

  • Mathematica
    Table[Select[FromDigits/@Tuples[{4,5,6},n],OddQ[Sqrt[8#+1]]&],{n,17}]//Flatten (* Harvey P. Dale, Aug 28 2023 *)

Formula

a(n) = A000217(A119203(n)). - Tyler Busby, Mar 25 2023

Extensions

a(24)-a(25) from Tyler Busby, Mar 25 2023

A136812 Numbers k such that k and k^2 use only the digits 0, 1, 2, 3 and 6.

Original entry on oeis.org

0, 1, 6, 10, 11, 60, 100, 101, 106, 110, 111, 361, 600, 601, 1000, 1001, 1006, 1010, 1011, 1060, 1100, 1101, 1106, 1110, 1631, 3606, 3610, 6000, 6001, 6010, 6011, 10000, 10001, 10006, 10010, 10011, 10060, 10100, 10101, 10106, 10110, 10111, 10301, 10306, 10600, 11000, 11001, 11006, 11010, 11060, 11100, 11101, 16310, 32111, 36060, 36100, 36361
Offset: 1

Views

Author

Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008

Keywords

Comments

Generated with DrScheme.

Examples

			1031316261^2 = 1063613230203020121.

Links

Crossrefs

Cf. A136808, ..., A137147.
Cf. A006716 = A027675^2, A030174 = A030175^2, A030176 = A030177^2, A058411^2 = A058412, ..., A058473^2 = A058474.
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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