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 1-2 of 2 results.

A119176 Triangular numbers composed of digits {2,6,9}.

Original entry on oeis.org

6, 66, 666, 2926, 29962999696266, 226966926929226, 9996922966699222296, 296292269222296622226, 22266696966226666966622226, 266669269626696962299266226222926
Offset: 1

Views

Author

Giovanni Resta, May 10 2006

Keywords

Comments

a(11) > 10^40. - Tyler Busby, Mar 28 2023

Links

Crossrefs

Cf. A000217, A053931, A119177. See A119033 for a table of cross-references.

Formula

a(n) = A000217(A119177(n)). - Tyler Busby, Mar 28 2023

Extensions

a(10) from Tyler Busby, Mar 28 2023

A053930 Numbers k such that k^2 contains only digits {2,6,9}.

Original entry on oeis.org

3, 173, 264, 964, 3114, 31563, 163187, 264437, 16431563, 96032404423, 99647694036, 9813067816077, 51665201022187, 51960847753114, 7935361806302386, 78883604126137785577, 47567102808870567435673, 26395073915340646948470264
Offset: 1

Views

Author

Patrick De Geest, Mar 15 2000

Keywords

Links

Crossrefs

Cf. A053931.

Programs

  • PARI
    isok(n) = {digs = digits(n^2); for (i = 1, #digs, if ((digs[i] != 2) && (digs[i] != 6) && (digs[i] != 9), return (0));); return (1);} \\ Michel Marcus, Sep 02 2013

Extensions

More terms from Joe K. Crump (joecr(AT)carolina.rr.com), Sep 07 2000
a(17)-a(19) from Zhao Hui Du, Mar 01 2024
Showing 1-2 of 2 results.

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

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