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.

A060036 Triangular array T read by rows: T(n,k) = k^2 mod n, for k = 1,2,...,n-1, n = 2,3,...

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Mar 17 2001

Keywords

Comments

T(n,k) = A048152(n-1,k), 1 <= k < n; T(2*n-1,n-1) = A123684(n-1) = A225126(n-1). - Reinhard Zumkeller, Apr 29 2013

Examples

			The triangle T(n,k) begins:
n\k 1 2 3 4 5 6 7 8 9 10 11 ...
-------------------------------
2:  1
3:  1 1
4:  1 0 1
5:  1 4 4 1
6:  1 4 3 4 1
7:  1 4 2 2 4 1
6:  1 4 1 0 1 4 1
9:  1 4 0 7 7 0 4 1
10: 1 4 9 6 5 6 9 4 1
11: 1 4 9 5 3 3 5 9 4  1
12: 1 4 9 4 1 0 1 4 9  4  1
...  reformatted by - _Wolfdieter Lang_, Dec 17 2018
		

Crossrefs

Cf. A048153 (row sums).

Programs

  • Haskell
    a060036 n k = a060036_tabl !! (n-2) !! (k-1)
    a060036_row n = a060036_tabl !! (n-2)
    a060036_tabl = map init $ tail a048152_tabl
    -- Reinhard Zumkeller, Apr 29 2013
  • Mathematica
    Flatten[Table[PowerMod[k,2,n],{n,2,20},{k,n-1}]] (* Harvey P. Dale, Feb 27 2012 *)
  • PARI
    { n=1; for (m=2, 46, for (k=1, m-1, write("b060036.txt", n++, " ", k^2 % m)); ) } \\ Harry J. Smith, Jul 01 2009
    

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Mar 20 2001

A030068 The "semi-Fibonacci numbers": a(n) = A030067(2n - 1), where A030067 is the semi-Fibonacci sequence.

Original entry on oeis.org

1, 2, 3, 5, 6, 9, 11, 16, 17, 23, 26, 35, 37, 48, 53, 69, 70, 87, 93, 116, 119, 145, 154, 189, 191, 228, 239, 287, 292, 345, 361, 430, 431, 501, 518, 605, 611, 704, 727, 843, 846, 965, 991, 1136, 1145, 1299, 1334, 1523, 1525, 1716, 1753, 1981, 1992, 2231, 2279, 2566
Offset: 1

Views

Author

Keywords

Comments

Also the unique values of A030067 sorted. - Ralf Stephan, Oct 28 2013
Also, the subsequence of record values of the semi-Fibonacci sequence A030067.
The first differences of this sequence give back A030067. - It is more natural to use offset 1 and a(n) = A060037(2n-1), rather than 0 and a(n) = A060037(2n+1): First, a set should have this offset, and this is indeed the set of values or the range of A030067, i.e., the set of semi-Fibonacci numbers. Second, A060037 also starts at index 1. Third, the sequence A284282(n) = (k such that A030067(2k-1)=n or 0 if there's no such k) is then the characteristic function of this sequence, with nonzero values read as 1. - M. F. Hasler, Mar 24 2017

Crossrefs

Cf. A030067. Bisections: A169739, A169740.

Programs

Formula

G.f.: x*(r(x) * r(x^2) * r(x^4) * r(x^8) * ...) where r(x) is (1 + 2x + x^2 + x^3 + x^4 + x^5 + ...). - Gary W. Adamson, Sep 02 2016
a(n+1) = a(n) + A060037(n). The above g.f. can be written as x*Product_{k=0,oo} (1/(1-x^2^k)+x^2^k). - M. F. Hasler, Mar 27 2017

Extensions

Offset changed to 1 by N. J. A. Sloane, Mar 27 2017
Showing 1-2 of 2 results.