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.

A322561 Digits of one of the two 17-adic integers sqrt(2) that is related to A322559.

Original entry on oeis.org

6, 14, 14, 8, 5, 4, 14, 14, 7, 2, 15, 15, 11, 5, 6, 7, 2, 14, 6, 14, 15, 16, 3, 8, 14, 5, 12, 16, 0, 4, 7, 0, 8, 10, 2, 16, 16, 15, 9, 7, 12, 9, 14, 14, 5, 12, 3, 4, 7, 9, 9, 2, 2, 14, 5, 9, 12, 6, 2, 10, 5, 0, 10, 10, 11, 11, 2, 3, 14, 10, 11, 2, 6, 12, 0, 4
Offset: 0

Views

Author

Jianing Song, Aug 29 2019

Keywords

Comments

This square root of 2 in the 17-adic field ends with digit 6. The other, A322562, ends with digit 11 (B when written as a 17-adic number).

Examples

			The solution to x^2 == 2 (mod 17^4) such that x == 6 (mod 17) is x == 43594 (mod 17^4), and 43594 is written as 8EE6 in heptadecimal, so the first four terms are 6, 14, 14 and 8.
		

Crossrefs

Digits of 17-adic square roots:
A309989, A309990 (sqrt(-1));
this sequence, A322562 (sqrt(2));
A322565, A322566 (sqrt(-2)).

Programs

  • PARI
    a(n) = truncate(sqrt(2+O(17^(n+1))))\17^n

Formula

a(n) = (A322559(n+1) - A322559(n))/17^n.
For n > 0, a(n) = 16 - A322562(n).

A322565 Digits of one of the two 17-adic integers sqrt(-2) that is related to A322563.

Original entry on oeis.org

7, 1, 12, 0, 9, 0, 16, 8, 5, 16, 14, 0, 1, 15, 11, 16, 15, 8, 13, 15, 11, 5, 11, 3, 9, 16, 16, 15, 3, 3, 0, 15, 7, 15, 16, 3, 14, 9, 12, 5, 2, 2, 4, 12, 12, 11, 11, 0, 9, 15, 12, 2, 9, 14, 2, 10, 6, 0, 8, 5, 15, 6, 6, 14, 9, 2, 10, 1, 7, 2, 13, 12, 3, 13, 6, 16
Offset: 0

Views

Author

Jianing Song, Aug 29 2019

Keywords

Comments

This square root of -2 in the 17-adic field ends with digit 7. The other, A322566, ends with digit 10 (A when written as a 17-adic number).

Examples

			The solution to x^2 == -2 (mod 17^4) such that x == 7 (mod 17) is x == 3492 (mod 17^4), and 3492 is written as C17 in heptadecimal, so the first four terms are 7, 1, 12 and 0.
		

Crossrefs

Digits of 17-adic square roots:
A309989, A309990 (sqrt(-1));
A322561, A322562 (sqrt(2));
this sequence, A322566 (sqrt(-2)).

Programs

  • PARI
    a(n) = truncate(sqrt(-2+O(17^(n+1))))\17^n

Formula

a(n) = (A322563(n+1) - A322563(n))/17^n.
For n > 0, a(n) = 16 - A322566(n).

A322566 Digits of one of the two 17-adic integers sqrt(-2) that is related to A322564.

Original entry on oeis.org

10, 15, 4, 16, 7, 16, 0, 8, 11, 0, 2, 16, 15, 1, 5, 0, 1, 8, 3, 1, 5, 11, 5, 13, 7, 0, 0, 1, 13, 13, 16, 1, 9, 1, 0, 13, 2, 7, 4, 11, 14, 14, 12, 4, 4, 5, 5, 16, 7, 1, 4, 14, 7, 2, 14, 6, 10, 16, 8, 11, 1, 10, 10, 2, 7, 14, 6, 15, 9, 14, 3, 4, 13, 3, 10, 0
Offset: 0

Views

Author

Jianing Song, Aug 29 2019

Keywords

Comments

This square root of -2 in the 17-adic field ends with digit 10 (A when written as a 17-adic number). The other, A322565, ends with digit 7.

Examples

			The solution to x^2 == -2 (mod 17^4) such that x == 10 (mod 17) is x == 80029 (mod 17^4), and 80029 is written as G4FA in heptadecimal, so the first four terms are 10, 15, 4 and 16.
		

Crossrefs

Digits of 17-adic square roots:
A309989, A309990 (sqrt(-1));
A322561, A322562 (sqrt(2));
A322565, this sequence (sqrt(-2)).

Programs

  • PARI
    a(n) = truncate(-sqrt(-2+O(17^(n+1))))\17^n

Formula

a(n) = (A322564(n+1) - A322564(n))/17^n.
For n > 0, a(n) = 16 - A322565(n).

A322559 One of the two successive approximations up to 17^n for 17-adic integer sqrt(2). This is the 6 (mod 17) case (except for n = 0).

Original entry on oeis.org

0, 6, 244, 4290, 43594, 461199, 6140627, 344066593, 6088808015, 54919110102, 292094863096, 30532003369831, 544610447984326, 6953455057511697, 56476345222041382, 1066743304578446956, 21103704665147157507, 118426088416480894469, 11699789754825195592947
Offset: 0

Views

Author

Jianing Song, Aug 29 2019

Keywords

Comments

For n > 0, a(n) is the unique solution to x^2 == 2 (mod 17^n) in the range [0, 17^n - 1] and congruent to 6 modulo 17.
A322560 is the approximation (congruent to 11 mod 17) of another square root of 2 over the 17-adic field.

Examples

			6^2 = 36 = 2*17 + 2;
244^2 = 59536 = 206*17^2 + 2;
4290^2 = 18404100 = 3746*17^3 + 2.
		

Crossrefs

Approximations of 17-adic square roots:
A286877, A286878 (sqrt(-1));
this sequence, A322560 (sqrt(2));
A322563, A322564 (sqrt(-2)).

Programs

  • PARI
    a(n) = truncate(sqrt(2+O(17^n)))

Formula

For n > 0, a(n) = 17^n - A322560(n).
a(n) = Sum_{i=0..n-1} A322561(i)*17^i.
a(n) = A286877(n)*A322564(n) mod 17^n = A286878(n)*A322563(n) mod 17^n.

A322560 One of the two successive approximations up to 17^n for 17-adic integer sqrt(2). This is the 11 (mod 17) case (except for n = 0).

Original entry on oeis.org

0, 11, 45, 623, 39927, 958658, 17996942, 66272080, 886949426, 63668766395, 1723899037353, 3739892937802, 38011789245435, 2951122975394240, 111901481337359547, 1795679746931368837, 27557487210519710974, 708814173469855869708, 2363294697242529398062
Offset: 0

Views

Author

Jianing Song, Aug 29 2019

Keywords

Comments

For n > 0, a(n) is the unique solution to x^2 == 2 (mod 17^n) in the range [0, 17^n - 1] and congruent to 11 modulo 17.
A322559 is the approximation (congruent to 6 mod 17) of another square root of 2 over the 17-adic field.

Examples

			11^2 = 121 = 7*17 + 2;
45^2 = 2025 = 7*17^2 + 2;
623^2 = 388129 = 79*17^3 + 2.
		

Crossrefs

Approximations of 17-adic square roots:
A286877, A286878 (sqrt(-1));
A322559, this sequence (sqrt(2));
A322563, A322564 (sqrt(-2)).

Programs

  • PARI
    a(n) = truncate(-sqrt(2+O(17^n)))

Formula

For n > 0, a(n) = 17^n - A322559(n).
a(n) = Sum_{i=0..n-1} A322562(i)*17^i.
a(n) = A286877(n)*A322563(n) mod 17^n = A286878(n)*A322564(n) mod 17^n.
Showing 1-5 of 5 results.