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.

A321078 Digits of one of the two 11-adic integers sqrt(5).

Original entry on oeis.org

4, 4, 10, 4, 0, 9, 5, 8, 7, 7, 3, 9, 7, 4, 1, 8, 10, 5, 10, 8, 10, 2, 5, 6, 10, 10, 3, 10, 2, 2, 1, 6, 6, 5, 7, 10, 0, 6, 9, 8, 3, 1, 6, 5, 3, 1, 9, 0, 5, 8, 8, 10, 4, 8, 9, 1, 9, 7, 1, 2, 1, 0, 5, 0, 2, 9, 1, 5, 2, 1, 3, 1, 7, 10, 3, 5, 0, 4, 10, 5, 1, 2, 10, 2, 1, 3, 0
Offset: 0

Views

Author

Jianing Song, Oct 27 2018

Keywords

Comments

This square root of 5 in the 11-adic field ends with digit 4. The other, A321079, ends with digit 7.

Examples

			...8960A7566122A3AA652A8A5A8147937785904A44.
		

Crossrefs

Programs

  • PARI
    a(n) = truncate(sqrt(5+O(11^(n+1))))\11^n

Formula

a(n) = (A321076(n+1) - A321076(n))/11^n.
For n > 0, a(n) = 10 - A321079(n).

A321077 One of the two successive approximations up to 11^n for 11-adic integer sqrt(5). Here the 7 (mod 11) case (except for n = 0).

Original entry on oeis.org

0, 7, 73, 73, 8059, 154469, 315520, 9173325, 48147667, 691224310, 7765067383, 189327039590, 474638710201, 9889923840364, 217026196703950, 3634774698953119, 11989271037784421, 11989271037784421, 2539224413534253276, 2539224413534253276, 124857405310363345858
Offset: 0

Views

Author

Jianing Song, Oct 27 2018

Keywords

Comments

For n > 0, a(n) is the unique solution to x^2 == 5 (mod 11^n) in the range [0, 11^n - 1] and congruent to 7 modulo 11.
A321076 is the approximation (congruent to 4 mod 11) of another square root of 5 over the 11-adic field.

Examples

			7^2 = 49 = 5 + 4*11.
73^2 = 5329 = 5 + 44*11^2 = 5 + 4*11^3.
		

Crossrefs

Programs

  • PARI
    a(n) = truncate(-sqrt(5+O(11^n)))

Formula

For n > 0, a(n) = 11^n - A321076(n).
a(n) = Sum_{i=0..n-1} A321079(i)*11^i.
Showing 1-2 of 2 results.