A026100 a(n) = number of the column of A026098 that contains n.
1, 2, 1, 3, 1, 2, 1, 4, 3, 2, 1, 4, 1, 2, 3, 5, 1, 5, 1, 4, 3, 2, 1, 6, 5, 2, 6, 4, 1, 7, 1, 8, 3, 2, 5, 7, 1, 2, 3, 6, 1, 6, 1, 4, 7, 9, 1, 8, 7, 8, 3, 4, 1, 9, 5, 10, 3, 2, 1, 9, 1, 11, 8, 12, 5, 6, 1, 4, 2, 9, 1, 10, 1, 2, 10, 4, 7, 6, 1, 11, 11, 13, 1, 10, 5, 14, 3, 8, 1, 12, 7, 3, 2, 15, 5, 13, 1, 11, 9, 12
Offset: 1
Links
- Antti Karttunen, Table of n, a(n) for n = 1..19477
Crossrefs
Cf. A026098.
Programs
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PARI
getrow(n, all) = {if (n==1, return ([1])); if (n==2, return ([3, 2])); my(row = vector(n)); row[1] = prime(n); for (k=2, n, my(ok = 0, m = 1, val); until(ok, val = m*prime(n+1-k); if (!setsearch(all, val) && !setsearch(Set(row), val), ok = 1); m++; ); row[k] = val; ); return (row); }; A026100list(up_to_row) = { my(all = [], m = Map(), lista = List([]), u); for(n=1, up_to_row, my(row = getrow(n, all)); for(k=1, n, mapput(m,row[k],k)); all = Set(concat(all, row))); for(n=1,oo,if(mapisdefined(m,n,&u), listput(lista,u), if(isprime(n)&&(n>2),listput(lista,1), return(Vec(lista))))); }; v026100 = A026100list(1200); A026100(n) = v026100[n]; \\ Antti Karttunen, Jan 18 2020, after program in A026098 provided by Michel Marcus.
Extensions
a(27) onward corrected by Sean A. Irvine, Sep 15 2019
Comments