A344595 Numbers k such that A011772(k) > A344878(k) and A011772(k) is a divisor of A344875(k).

900, 1260, 1302, 1560, 2100, 3906, 4440, 6300, 6552, 6669, 9680, 11544, 12987, 15368, 18981, 19240, 19880, 24120, 26208, 35784, 36080, 42680, 46104, 57720, 59040, 59640, 62238, 62244, 71136, 74592, 76840, 79376, 81872, 84700, 101680, 103730, 108500, 124488, 128040, 145188, 160160, 168020, 171740, 178920, 185724, 201608

Offset

1,1

Comments

Numbers k for which A344973(k) = 0 and A344976(k) < 0.

It seems that in these cases, by necessity A011772(k) < A344875(k), i.e., A011772(k) is a proper divisor of A344875(k).

Has many terms common with A344694.

Links

Table of n, a(n) for n=1..46.

Prog

(PARI)
A011772(n) = { if(n==1, return(1)); my(f=factor(if(n%2, n, 2*n)), step=vecmax(vector(#f~, i, f[i, 1]^f[i, 2]))); forstep(m=step, 2*n, step, if(m*(m-1)/2%n==0, return(m-1)); if(m*(m+1)/2%n==0, return(m))); }; \\ From A011772
A344875(n) = { my(f=factor(n)~); prod(i=1, #f, (f[1, i]^(f[2, i]+(2==f[1, i]))-1)); };
A344878(n) = if(1==n, n, my(f=factor(n)~); lcm(vector(#f, i, (f[1, i]^(f[2, i]+(2==f[1, i]))-1))));
isA344595(n) = { my(u=A011772(n)); (u>A344878(n)&&0==(A344875(n)%u)); };

Crossrefs

Cf. A011772, A344694, A344875, A344878, A344973, A344976.

Intersection of A024619, A344974 and A344977.

Intersection of A344975 and A344977.

Sequence in context: A158408 A158409 A061044 * A344694 A127658 A318720

Adjacent sequences: A344592 A344593 A344594 * A344596 A344597 A344598

Keyword

nonn

Author

Antti Karttunen, Jun 05 2021

Status

approved