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A358760
Numbers k for which A349905(k) is a multiple of 4, where A349905(k) is the arithmetic derivative applied to the prime shifted k.
6
1, 6, 15, 16, 21, 22, 26, 36, 40, 46, 51, 55, 56, 57, 62, 65, 74, 77, 81, 87, 90, 91, 94, 96, 100, 115, 118, 123, 126, 129, 132, 136, 140, 142, 152, 155, 156, 159, 161, 166, 178, 183, 185, 187, 194, 196, 201, 209, 214, 216, 217, 218, 219, 221, 225, 232, 235, 237, 240, 247, 250, 256, 259, 262, 276
OFFSET
1,2
COMMENTS
Numbers k such that A003961(k) is one of the terms of A327864.
Numbers k such that A001222(k) == A003961(k)-1 (modulo 4).
FORMULA
{k | A010873(A349905(k)) = 0}.
MAPLE
filter:= proc(n) local m, np, F, F1, F2, i;
F:= ifactors(n)[2];
m:= nops(F);
F1:= map(nextprime, F[.., 1]);
F2:= F[.., 2];
np:= mul(F1[i]^F2[i], i=1..m);
np*add(F2[i]/F1[i], i=1..m) mod 4 = 0;
end proc:
select(filter, [$1..1000]); # Robert Israel, Nov 29 2023
PROG
(PARI) isA358760(n) = A358750(n);
CROSSREFS
Cf. A001222, A003415, A003961, A010873, A121262, A246260, A327864, A349905, A358750 (characteristic function).
Setwise difference A028260 \ A358762.
Cf. also A358761, A358763.
Sequence in context: A199223 A199094 A009579 * A114812 A158338 A373257
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 29 2022
STATUS
approved