login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A196942 a(n) is the prime order of sequence A196941. 1
0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 2, 2, 1, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 3, 3, 1, 2, 2, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 1, 1, 1, 2, 1, 3, 2, 4, 1, 2, 2, 2, 2, 3, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,6

COMMENTS

Assuming 1 is the 0th prime, as what in Mathematica: PrimePi[1] = 0.

So far the first occurrence of this sequence agree with A062241 and A045535.  Is this a coincidence or a theorem?

LINKS

Table of n, a(n) for n=2..88.

EXAMPLE

A196941(3) = 2, which is the first prime number, so a(3) = 1;

MATHEMATICA

FactorSet[seed_] := Module[{fset2, a, l, i}, a = FactorInteger[seed]; l = Length[a]; fset2 = {}; Do[fset2 = Union[fset2, {a[[i]][[1]]}], {i, 1, l}]; fset2]; Table[min = n; Do[r = n - k; s = Union[FactorSet[k], FactorSet[r]]; If[a = s[[Length[s]]]; a < min, min = a], {k, 1, IntegerPart[n/2]}]; PrimePi[min], {n, 2, 88}]

CROSSREFS

Cf. A196941, A062241.

Sequence in context: A212185 A270928 A290257 * A184304 A025909 A025899

Adjacent sequences:  A196939 A196940 A196941 * A196943 A196944 A196945

KEYWORD

nonn,easy

AUTHOR

Lei Zhou, Oct 07 2011

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified September 20 01:58 EDT 2019. Contains 327207 sequences. (Running on oeis4.)