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 1-5 of 5 results.

A138072 Triangle read by rows: row n lists the digits of A135700(n), the palindromic number formed from the reflected decimal expansion of golden ratio phi.

Original entry on oeis.org

1, 1, 1, 1, 6, 1, 1, 6, 6, 1, 1, 6, 1, 6, 1, 1, 6, 1, 1, 6, 1, 1, 6, 1, 8, 1, 6, 1, 1, 6, 1, 8, 8, 1, 6, 1, 1, 6, 1, 8, 0, 8, 1, 6, 1, 1, 6, 1, 8, 0, 0, 8, 1, 6, 1, 1, 6, 1, 8, 0, 3, 0, 8, 1, 6, 1, 1, 6, 1, 8, 0, 3, 3, 0, 8, 1, 6, 1
Offset: 1

Views

Author

Omar E. Pol, Mar 03 2008

Keywords

Comments

Also, successive digits of the numbers A135700(n).

Examples

			Triangle begins:
...... 1
..... 1,1
.... 1,6,1
... 1,6,6,1
.. 1,6,1,6,1

Crossrefs

Decimal expansion of phi: A001622. Cf. A135699, A135700, A135696, A138073.

A011551 Decimal expansion of phi truncated to n places.

Original entry on oeis.org

1, 16, 161, 1618, 16180, 161803, 1618033, 16180339, 161803398, 1618033988, 16180339887, 161803398874, 1618033988749, 16180339887498, 161803398874989, 1618033988749894, 16180339887498948, 161803398874989484, 1618033988749894848, 16180339887498948482
Offset: 0

Views

Author

N. J. A. Sloane

Keywords

Links

Crossrefs

Cf. A001622 (phi), A138116 (triangle of digits), A195607 (fraction), A276198 (next prime).
Palindromes: A135699, A135700.

Programs

  • Mathematica
    With[{phi=RealDigits[GoldenRatio,10,50][[1]]},Table[FromDigits[ Take[ phi,n]],{n,20}]] (* Harvey P. Dale, Feb 03 2012 *)
  • PARI
    my(phi=quadgen(5)); a(n) = floor(phi*10^n); \\ Kevin Ryde, Jun 05 2021

A138073 Triangle read by rows: row n lists the digits of A135699(n), the palindromic number with odd number of digits formed from the reflected decimal expansion of golden ratio phi.

Original entry on oeis.org

1, 1, 6, 1, 1, 6, 1, 6, 1, 1, 6, 1, 8, 1, 6, 1, 1, 6, 1, 8, 0, 8, 1, 6, 1, 1, 6, 1, 8, 0, 3, 0, 8, 1, 6, 1, 1, 6, 1, 8, 0, 3, 3, 3, 0, 8, 1, 6, 1, 1, 6, 1, 8, 0, 3, 3, 9, 3, 3, 0, 8, 1, 6, 1, 1, 6, 1, 8, 0, 3, 3, 9, 8, 9, 3, 3, 0, 8, 1, 6, 1
Offset: 1

Views

Author

Omar E. Pol, Mar 03 2008

Keywords

Comments

Also, successive digits of the terms of A135699.

Examples

			Triangle begins:
.............. 1
........... 1, 6, 1
........ 1, 6, 1, 6, 1
..... 1, 6, 1, 8, 1, 6, 1
.. 1, 6, 1, 8, 0, 8, 1, 6, 1

Links

Crossrefs

Decimal expansion of phi: A001622. Cf. A135699, A135700, A138072.

Programs

  • Mathematica
    nn=10;With[{phi=RealDigits[GoldenRatio,10,nn+1][[1]]},Flatten[ Table[ Join[Take[phi,n],Take[phi,{n+1}],Reverse[Take[phi,n]]],{n,0,nn}]]] (* Harvey P. Dale, May 08 2012 *)

A139258 Palindromes formed from the reflected decimal expansion of Euler's constant (or Euler-Mascheroni constant) gamma.

Original entry on oeis.org

5, 55, 575, 5775, 57775, 577775, 5772775, 57722775, 577212775, 5772112775, 57721512775, 577215512775, 5772156512775, 57721566512775, 577215666512775, 5772156666512775, 57721566466512775, 577215664466512775
Offset: 1

Views

Author

Omar E. Pol, May 01 2008

Keywords

Examples

			n ... Successive digits of a(n)
1 ............ ( 5 )
2 ......... . ( 5 5 )
3 .......... ( 5 7 5 )
4 ......... ( 5 7 7 5 )
5 ........ ( 5 7 7 7 5 )
6 ....... ( 5 7 7 7 7 5 )
7 ...... ( 5 7 7 2 7 7 5 )
8 ..... ( 5 7 7 2 2 7 7 5 )
9 .... ( 5 7 7 2 1 2 7 7 5 )
10 .. ( 5 7 7 2 1 1 2 7 7 5 )

Crossrefs

Decimal expansion of gamma: A001620. Cf. A135634, A135697, A135700, A139259, A139260, A139261.

Programs

  • Mathematica
    a[n_]:=FromDigits[Join[RealDigits[EulerGamma,10,Ceiling[n/2]][[1]],Reverse[RealDigits[EulerGamma,10,Floor[n/2]][[1]]]]];Array[a,18] (* James C. McMahon, Jun 29 2025 *)

A383404 Palindromic primes formed from the reflected decimal expansion of the golden ratio phi.

Original entry on oeis.org

11, 1618033308161, 16180339887498948482045868343656381118365634386854028484989478893308161, 16180339887498948482045868343656381177203030277118365634386854028484989478893308161
Offset: 1

Views

Author

Omar E. Pol, May 06 2025

Keywords

Comments

Primes in A135700.
Terms with an odd number of digits are the primes in A135699.

Links

Crossrefs

Cf. A001622, A002113, A002385, A039954, A135699, A135700.
Showing 1-5 of 5 results.

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

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