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A354218
Records in A076978, divided by 2.
3
1, 3, 15, 105, 1155, 1365, 19635, 23205, 636405, 10555545, 24484845, 869107785, 14797252681546335, 92442344345566215, 40334203530676690635, 1451417351374223318085, 6087255082617244520985, 469256253416014832182075245585, 1519012498286389398934397206158552189345
OFFSET
1,2
LINKS
MATHEMATICA
1/2*Union@ FoldList[Max, Array[Times @@ FactorInteger[Times @@ Range[#1 + 1, #2 - 1]][[All, 1]] & @@ Map[Prime, # + {0, 1}] &, 180, 2]] (* Michael De Vlieger, May 20 2022 *)
PROG
(Python)
from sympy import sieve as p, primefactors
def A076978_halfen(n): # for all integers n > 1
result = 1
for composites in range(p[n]+1, p[n+1]):
for primefactor in primefactors(composites):
if result % primefactor != 0: result *= primefactor
return result//2
A354218 = [1]
for n in range(2, 180):
if A076978_halfen(n) > A354218[-1]: A354218.append(A076978_halfen(n))
print(A354218) # Karl-Heinz Hofmann, May 20 2022
(PARI) a354218(maxterm) = {my(mp=0, pp=3); forprime(p=5, oo, my(L=List()); for(j=pp+1, p-1, my(f=factor(j), nf=#f~); for(k=1, nf, listput(~L, f~[1, k]))); listsort(L, 1); my(mpp=prod(k=1, #L, L[k])); if(mpp>mp, if(mpp<2*maxterm, print1(mpp/2, ", "); mp=mpp, return)); pp=p)};
a354218(10^75)
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, May 19 2022
STATUS
approved