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”).

A373225
Primes p = prime(k) such that 0 = Sum_{j=1..k} T(k, j) where T(n, k) = K(prime(n), prime(k)) * K(prime(k), prime(n)) and K is the Kronecker symbol.
4
2, 11, 23, 31, 47, 59, 67, 103, 127, 419, 431, 439, 467, 1259, 1279, 1303, 26947, 615883, 616787, 617051, 617059, 617087, 617647, 617731, 617819, 617879, 618463, 618559, 618587, 618671, 620467, 623867, 623879, 624199, 624271, 624311, 624319, 624331, 626887, 626987, 627071
OFFSET
1,1
COMMENTS
It appears that, apart from 1st term 2, this is a subsequence of A096448. - Michel Marcus, May 30 2024
For n > 2, the sequence is exactly those terms p in A096448 with p == 3 (mod 4); see linked proof. - Michael S. Branicky, May 30 2024
LINKS
Michael S. Branicky, Proof for A373225
EXAMPLE
The corresponding indices in A373224 start: 1, 5, 9, 11, 15, 17, 19, 27, 31, 81, 83, 85, 91, 205, 207, 213.
T(k, j) defined as in the name. 11 is a term because 11 = prime(5) and Sum_{j=1..5} T(k, j) = 1 + (-1) + 1 + (-1) + 0 = 0.
MAPLE
A := select(n -> A373224(n) = 0, [seq(1..500)]):
seq(ithprime(a), a in A);
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, May 29 2024
EXTENSIONS
a(17) onward from Michel Marcus, May 30 2024
STATUS
approved