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.

A284563 a(n) = A247503(A277324(n)).

Original entry on oeis.org

2, 2, 2, 10, 10, 10, 50, 10, 10, 250, 250, 50, 250, 250, 50, 110, 110, 250, 6250, 1250, 1250, 31250, 6250, 550, 2750, 6250, 6250, 13750, 2750, 2750, 6050, 110, 110, 30250, 68750, 13750, 343750, 781250, 156250, 151250, 151250, 781250, 19531250, 1718750, 343750, 8593750, 756250, 6050, 30250, 756250, 1718750, 3781250, 3781250, 8593750, 18906250, 151250
Offset: 0

Views

Author

Antti Karttunen, Mar 29 2017

Keywords

Crossrefs

Odd bisection of A284553.

Programs

  • Mathematica
    a[n_] := a[n] = Which[n < 2, n + 1, EvenQ@ n, Times @@ Map[#1^#2 & @@ # &, FactorInteger[#] /. {p_, e_} /; e > 0 :> {Prime[PrimePi@ p + 1], e}] - Boole[# == 1] &@ a[n/2], True, a[#] a[# + 1] &[(n - 1)/2]]; Table[Times @@ (FactorInteger[#] /. {p_, e_} /; e > 0 :> (p^Mod[PrimePi@ p, 2])^e) &@ a[2 n + 1], {n, 0, 55}] (* Michael De Vlieger, Apr 05 2017 *)
  • PARI
    A284563(n) = A284553(n+n+1); \\ Other code as in A284553.
    
  • Scheme
    (define (A284563 n) (A247503 (A277324 n)))
    (define (A284563 n) (A284553 (+ n n 1)))

Formula

a(n) = A247503(A277324(n)).
a(n) = A284553((2*n)+1).
Other identities. For all n >= 0:
A001222(a(n)) = A284565(n).