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A356414
Number k such that k and k+1 both have an equal sum of even and odd exponents in their prime factorization (A356413).
1
819, 1035, 1196, 1274, 1275, 1449, 1665, 1924, 1925, 1988, 2324, 2331, 2540, 3068, 3195, 3324, 3339, 3549, 3555, 3626, 3717, 4164, 4220, 4235, 4556, 4598, 4635, 4675, 4796, 5084, 5525, 5634, 5660, 6003, 6027, 6068, 6164, 6363, 6740, 6867, 6908, 7028, 7227, 7275
OFFSET
1,1
COMMENTS
Numbers k such that A350386(k) = A350387(k) and A350386(k+1) = A350387(k+1).
LINKS
EXAMPLE
819 is a term since A350386(819) = A350387(819) = 2 and A350386(820) = A350387(820) = 2.
MATHEMATICA
f[p_, e_] := (-1)^e*e; q[1] = True; q[n_] := Plus @@ f @@@ FactorInteger[n] == 0; Select[Range[10^4], q[#] && q[# + 1] &]
PROG
(PARI) is(n) = {my(f = factor(n)); sum(i = 1, #f~, (-1)^f[i, 2]*f[i, 2]) == 0};
is1 = is(1); for(k = 2, 10^4, is2 = is(k); if(is1 && is2, print1(k-1, ", ")); is1 = is2);
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Aug 06 2022
STATUS
approved