A336553 Odd numbers k such that gcd(A336551(k), A326143(k)) is equal to A336551(k).

45, 63, 99, 117, 147, 153, 171, 207, 261, 279, 315, 325, 333, 369, 387, 423, 425, 477, 495, 531, 549, 585, 603, 639, 657, 693, 711, 725, 735, 747, 765, 801, 819, 847, 855, 873, 909, 925, 927, 963, 981, 1017, 1025, 1035, 1071, 1125, 1143, 1179, 1197, 1233, 1251, 1287, 1305, 1325, 1341, 1359, 1395, 1413, 1449, 1467, 1503

Offset: 1

Author

Antti Karttunen, Jul 28 2020

Keywords

• nonn

Comments

Is the intersection with A336554 empty?

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Index entries for sequences where odd perfect numbers must occur, if they exist at all

Crossrefs

Odd terms in A336552.

Cf. A336554.

Programs

PARI

A007947(n) = factorback(factorint(n)[, 1]);
A326143(n) = (sigma(n)-A007947(n)-n);
A336551(n) = { my(f=factor(n)); for(i=1, #f~, f[i, 2] = f[i, 2]-1); (factorback(f)-1); };
isA336553(n) = if(!(n%2),0, my(u=A336551(n)); (u==gcd(u,A326143(n))));