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A340534
a(n) is the least product of n consecutive primes that is divisible by the sum of those primes, or 0 if there is no such product.
0
2, 0, 30, 0, 15015, 0, 37182145, 9699690, 33426748355, 0, 3710369067405, 0, 304250263527210, 0, 37420578814667938361329, 0, 18598027670889965365580513, 0, 107254825578022430263302818471, 0, 44510752614879308559270669665465, 0, 267064515689275851355624017992790, 0, 116431182179248680450031658440253681535, 0
OFFSET
1,1
COMMENTS
a(27) > 10^225 if it is not 0.
If n is even, a(n) is either A002110(n) or 0.
a(n) = A002110(n) for n in A051838.
EXAMPLE
a(5) = 15015 = 3*5*7*11*13 is the product of 5 consecutive primes and is divisible by 3+5+7+11+13 = 39.
MAPLE
f:= proc(n) local L, i, p;
L:= [seq(ithprime(i), i=1..n)]:
p:= convert(L, `*`);
if n::even then
if p mod convert(L, `+`) = 0 then return p else return 0 fi
else
do
p:= convert(L, `*`);
if p mod convert(L, `+`) = 0 then return p fi;
if p > 10^225 then return FAIL fi;
L:= [op(L[2..-1]), nextprime(L[-1])];
od
fi;
end proc:
map(f, [$1..26]);
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Jan 10 2021
STATUS
approved