login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A340541
Primes p such that the product of (p mod q) for primes q < p is a multiple of the sum of (p mod q) for primes q < p.
1
3, 11, 17, 31, 59, 67, 73, 101, 103, 173, 179, 193, 199, 211, 223, 349, 401, 463, 491, 499, 557, 563, 569, 571, 577, 587, 607, 613, 619, 631, 673, 709, 751, 757, 769, 797, 809, 857, 859, 877, 911, 919, 929, 967, 1009, 1033, 1039, 1049, 1151, 1153, 1193, 1201, 1237, 1249, 1259, 1289, 1297, 1303
OFFSET
1,1
COMMENTS
Primes prime(n) such that A102647(n) is divisible by A033955(n).
LINKS
EXAMPLE
a(3) = 17 is a term since (17 mod q) for primes q=2,3,5,7,11,13 are 1,2,2,3,6,4, and 1*2*2*3*6*4 = 288 is divisible by 1+2+2+3+6+4 = 18.
MAPLE
P:= [seq(ithprime(i), i=1..1000)]:
filter:= proc(n) local L, k;
L:= [seq(P[n] mod P[k], k=1..n-1)];
convert(L, `*`) mod convert(L, `+`) = 0
end proc:
S:=select(filter, [$2..1000]):
map(t -> P[t], S);
PROG
(PARI) isok(p) = {if (isprime(p) && (p>2), my(s=0, t=1); forprime(q=2, p-1, my(x= p%q); s += x; t *= x; ); !(t % s); ); } \\ Michel Marcus, Jan 11 2021
CROSSREFS
Sequence in context: A194800 A154501 A045432 * A186424 A018520 A154933
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Jan 11 2021
STATUS
approved