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.

A290960 Numbers k such that A276976(k) > A270096(k).

Original entry on oeis.org

8, 32, 56, 64, 96, 128, 144, 155, 170, 176, 192, 196, 204, 215, 221, 224, 238, 248, 255, 256, 272, 288, 320, 322, 336, 341, 352, 368, 372, 374, 384, 432, 448, 465, 476, 496, 510, 512, 527, 544, 574, 576, 608, 612, 623, 635, 640, 644, 645, 658, 663, 672, 682, 697, 704, 714, 731, 736, 744
Offset: 1

Views

Author

Altug Alkan, Aug 15 2017, following a suggestion from N. J. A. Sloane

Keywords

Comments

Odd terms are 155, 215, 221, 255, 341, 465, 527, 623, 635, 645, 663, ...
These odd terms are odd numbers k such that (k mod A002322(k)) > (k mod A002326((k-1)/2)). - Amiram Eldar and Thomas Ordowski, Nov 28 2019

Examples

			8 is a term because A276976(8) = 4 while A270096(8) = 3.
		

Crossrefs

Programs

  • Maple
    A270096:= proc(n) local d, b, t, m, c;
      d:= padic:-ordp(n, 2);
      b:= n/2^d;
      t:= 2 &^ n mod n;
      m:= numtheory:-mlog(t, 2, b, c);
      if m < d then m:= m + c*ceil((d-m)/c) fi;
      m
    end proc:
    A270096(1):= 0:
    A276976:= proc(n) local lambda;
      lambda:= numtheory:-lambda(n);
      if n mod lambda = 0 then lambda
      elif n mod 8 = 0 and (n-2) mod lambda = 0 then lambda+2
      else n mod lambda
      fi
    end proc:
    A276976(1):= 0:
    A276976(8):= 4:
    A276976(24):= 4:
    select(n -> A276976(n) > A270096(n), [$1..1000]); # Robert Israel, Aug 16 2017
  • Mathematica
    With[{nn = 750}, Select[Range@ nn, Function[n, SelectFirst[Range[nn/4 + 10], Function[m, AllTrue[Range[2, n - 1], PowerMod[#, m , n] == PowerMod[#, n , n] &]]] > SelectFirst[Range[nn/4 + 10], PowerMod[2, n, n] == PowerMod[2, #, n] &]]]] (* Michael De Vlieger, Aug 15 2017 *)