A377991 - OEIS

A377991

Numbers k such that A351568(k) and A351569(k) are not coprime, where A351568 and A351569 are the sum of divisors of the largest unitary divisor of n that is a square, and of the largest unitary divisor of n that is an exponentially odd number, respectively.

52, 98, 156, 164, 245, 260, 294, 332, 338, 364, 388, 392, 468, 490, 492, 539, 556, 572, 668, 722, 724, 735, 780, 820, 833, 845, 882, 884, 892, 927, 972, 976, 980, 988, 996, 1004, 1014, 1078, 1092, 1125, 1127, 1148, 1164, 1172, 1176, 1196, 1228, 1274, 1300, 1352, 1396, 1404, 1421, 1470, 1476, 1508, 1525, 1568, 1573

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OFFSET

1,1

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to sigma(n)

FORMULA

{k such that gcd(A351568(n),A351569(n)) > 1}.

{k such that A377990(k) > A051027(k)}.

EXAMPLE

A351568(52) = 7 and A351569(52) = 14, so they share a factor (7), and therefore 52 is included as a term.

PROG