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A317920 Length of row n of A317721, i.e., number of elements in n-th Wieferich tuple when ordering the tuples as in A317721. 8
3, 5, 6, 7, 6, 7, 3, 8, 9, 9, 10, 10, 11, 9, 2, 3, 6, 9, 10, 11, 12, 13, 14, 3, 3, 4, 4, 5, 5, 5, 5, 5, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..75.

EXAMPLE

For n = 1: Row 1 of A317721 has 3 elements, i.e., the first Wieferich tuple listed in A317721 is a "Wieferich triple", so a(1) = 3.

PROG

(PARI) addtovec(vec) = my(w=[], vmax=0); for(t=1, #vec, if(vecmax(vec[t]) > vmax, vmax=vecmax(vec[t]))); for(k=1, #vec, forprime(q=1, vmax, if(Mod(vec[k][#vec[k]], q^2)^(q-1)==1, w=concat(w, [0]); w[#w]=concat(vec[k], [q])))); w

removefromvec(vec) = my(w=[]); for(k=1, #vec, if(vecsort(vec[k])==vecsort(vec[k], , 8), w=concat(w, [0]); w[#w]=vec[k])); w

printfromvec(vec) = for(k=1, #vec, if(vec[k][1]==vec[k][#vec[k]], print1(#vec[k]-1, ", ")))

forprime(p=1, , my(v=[[p]]); while(#v > 0, v=addtovec(v); printfromvec(v); v=removefromvec(v)))

CROSSREFS

Cf. A297846, A317721, A317919.

Sequence in context: A181753 A082218 A111612 * A305443 A122818 A070083

Adjacent sequences:  A317917 A317918 A317919 * A317921 A317922 A317923

KEYWORD

nonn

AUTHOR

Felix Fröhlich, Aug 21 2018

STATUS

approved

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Last modified September 21 07:28 EDT 2021. Contains 347596 sequences. (Running on oeis4.)