A317919 Number of Wieferich tuples with A297846(n) as largest member, i.e., number of rows of the array in A317721 where A297846(n) is the largest element of that row.

1, 3, 2, 7, 1, 2, 1, 6, 1, 317, 1, 1, 230, 580

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Example

For n = 2: The second prime that occurs in column 1 of the array in A317721 is 359. 359 occurs as the largest element in 3 rows of the array, so a(2) = 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
forprime(p=1, , my(v=[[p]], i=0); while(#v > 0, v=addtovec(v); for(k=1, #v, if(v[k][1]==v[k][#v[k]], i++)); v=removefromvec(v)); if(i > 0, print1(i, ", ")))

Crossrefs

Cf. A297846, A317721, A317920.

Sequence in context: A330501 A010606 A348493 * A255820 A318436 A369042

Adjacent sequences: A317916 A317917 A317918 * A317920 A317921 A317922

Keyword

nonn,more

Author

Felix Fröhlich, Aug 21 2018

Status

approved