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A336553 Odd numbers k such that gcd(A336551(k), A326143(k)) is equal to A336551(k). 3
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

PROG

(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))));

CROSSREFS

Odd terms in A336552.

Cf. A336554.

Sequence in context: A321498 A051773 A307222 * A140278 A046426 A056776

Adjacent sequences:  A336550 A336551 A336552 * A336554 A336555 A336556

KEYWORD

nonn

AUTHOR

Antti Karttunen, Jul 28 2020

STATUS

approved

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Last modified June 24 21:50 EDT 2021. Contains 345433 sequences. (Running on oeis4.)