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 1-3 of 3 results.

A141269 (0, 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, ...) transform in (0+1, 2+3, 2+2, 5+2, 3+7, 2+3, 3+2, 2+5, 11+2, 2+3, ...).

Original entry on oeis.org

1, 5, 4, 7, 10, 5, 5, 7, 13, 5, 15, 10, 7, 21, 5, 21, 4, 8, 9, 34, 5, 8, 4, 16, 5, 9, 31, 8, 33, 8, 13, 22, 9, 5, 39, 21, 16, 5, 46, 5, 50, 4, 14, 7, 25, 49, 7, 9, 7, 5, 19, 15, 55, 6, 16, 5, 10, 21, 88, 4, 8, 63, 34, 9, 8, 18, 5, 78, 4, 20, 25, 12, 73, 6, 75, 39, 8, 4, 21, 18, 5, 92, 6, 8, 6
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Aug 08 2008

Keywords

Crossrefs

Extensions

Corrected at three or more places by R. J. Mathar, Feb 21 2009

A141270 (0, 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, ...) transform in (0*1, 2*3, 2*2, 5*2, 3*7, 2*3, 3*2, 2*5, 11*2, 2*3, ...).

Original entry on oeis.org

0, 6, 4, 10, 21, 6, 6, 10, 22, 6, 26, 21, 10, 68, 6, 38, 4, 15, 14, 253, 6, 15, 4, 39, 6, 14, 58, 15, 62, 15, 22, 85, 14, 6, 74, 38, 39, 6, 205, 6, 301, 4, 33, 10, 46, 94, 12, 14, 10, 6, 34, 26, 106, 9, 55, 6, 21, 38, 1711, 4, 15, 122, 93, 14, 12, 65, 6, 737, 4, 51, 46, 35, 142, 9
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Aug 08 2008

Keywords

Crossrefs

Programs

  • Mathematica
    Map[Times @@ # &, Partition[Flatten[{0}~Join~Array[DeleteCases[Flatten@ FactorInteger[#], 1] &, 72] /. {} -> {1}], 2, 2]] (* Michael De Vlieger, Oct 20 2021 *)

Extensions

A 65 replaced with 85, a 54 with 74, etc. by R. J. Mathar, Feb 21 2009

A144190 (0, 1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, ...) becomes (0 mod 1, 2 mod 3, 2 mod 2, 5 mod 2, 3 mod 7, 2 mod 3, 3 mod 2, 2 mod 5, 11 mod 2, 2 mod 3, ...).

Original entry on oeis.org

0, 2, 0, 1, 3, 2, 1, 2, 1, 2, 1, 1, 1, 4, 2, 2, 0, 2, 1, 11, 2, 3, 0, 1, 1, 2, 1, 3, 1, 2, 1, 2, 1, 2, 2, 2, 3, 2, 5, 2, 7, 0, 2, 2, 2, 1, 1, 1, 2, 2, 1, 2, 1, 0, 5, 2, 1, 1, 29, 0, 3, 1, 1, 2, 2, 5, 2, 11, 0, 2, 1, 5, 1, 0, 2, 2, 3, 0, 2, 7, 2, 13, 2, 2, 0, 41, 0, 3, 5, 2, 3, 2, 11, 2, 2, 7, 0, 2, 1, 2, 1, 2, 1
Offset: 1

Views

Author

Juri-Stepan Gerasimov, Nov 20 2008

Keywords

Examples

			2 mod 3 = 1 = a(10),
13 mod 2 = 1 = a(11),
7 mod 3 = 1 = a(12),
5 mod 2 = 1 = a(13),
4 mod 17 = 4 = a(14),
2 mod 3 = 2 = a(15),
2 mod 19 = 2 = a(16),
2 mod 2 = 0 = a(17),
5 mod 3 = 2 = a(18),
7 mod 2 = 1 = a(19),
11 mod 23 = 11 = a(20), etc.
		

Crossrefs

Programs

  • Maple
    pflat := proc(nmax) local a, ifs, n, p, c ; a := [0,1] ; for n from 2 to nmax do ifs := ifactors(n)[2] ; for p in ifs do a := [op(a),op(1,p)] ; if op(2,p) > 1 then a := [op(a),op(2,p)] ; fi; od: od: a ; end: L := pflat(300) ; for n from 1 to nops(L)-2 by 2 do printf("%d,", op(n,L) mod op(n+1,L) ) ; end do: # R. J. Mathar, Apr 29 2010

Extensions

a(10), a(43) and perhaps others corrected by R. J. Mathar, Apr 29 2010
Showing 1-3 of 3 results.