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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A364551 Odd numbers k such that k is a multiple of A005941(k).

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%I A364551 #14 Jul 29 2023 14:36:02
%S A364551 1,3,5,3125,7875,12005,13365,22869,23595,46475,703395,985439,2084775,
%T A364551 2675673,13619125,19144125
%N A364551 Odd numbers k such that k is a multiple of A005941(k).
%C A364551 Odd numbers k such that k is a multiple of 1+A156552(k).
%C A364551 Sequence A005940(A364545(n)) sorted into ascending order.
%C A364551 This is a subsequence of A364561, so the comments given in A364564 apply also here (see also the example section).
%e A364551 In all these cases, the right hand side is a divisor of the left hand side:
%e A364551       Term   (and its factorization)             A005941(term)
%e A364551          1   (unity)                         ->    1
%e A364551          3   (prime)                         ->    3
%e A364551          5   (prime)                         ->    5
%e A364551       3125 = 5^5                             ->    125 = 5^3
%e A364551       7875 = 3^2 * 5^3 * 7                   ->    375 = 3 * 5^3
%e A364551      12005 = 5 * 7^4                         ->    245 = 5 * 7^2
%e A364551      13365 = 3^5 * 5 * 11                    ->    1215 = 3^5 * 5
%e A364551      22869 = 3^3 * 7 * 11^2                  ->    847 = 7 * 11^2
%e A364551      23595 = 3 * 5 * 11^2 * 13               ->    715 = 5 * 11 * 13
%e A364551      46475 = 5^2 * 11 * 13^2                 ->    845 = 5 * 13^2
%e A364551     703395 = 3^2 * 5 * 7^2 * 11 * 29         ->    33495 = 3 * 5 * 7 * 11 * 29
%e A364551     985439 = 7^3 * 13^2 * 17                 ->    2873 = 13^2 * 17
%e A364551    2084775 = 3 * 5^2 * 7 * 11 * 19^2         ->    12635 = 5 * 7 * 19^2
%e A364551    2675673 = 3^5 * 7 * 11^2 * 13             ->    11583 = 3^4 * 11 * 13
%e A364551   13619125 = 5^3 * 13 * 17^2 * 29            ->    36125 = 5^3 * 17^2
%e A364551   19144125 = 3^2 * 5^3 * 7 * 11 * 13 * 17    ->    21879 = 3^2 * 11 * 13 * 17.
%o A364551 (PARI) A005941(n) = { my(f=factor(n), p, p2=1, res=0); for(i=1, #f~, p = 1 << (primepi(f[i, 1])-1); res += (p * p2 * (2^(f[i, 2])-1)); p2 <<= f[i, 2]); (1+res) }; \\ (After _David A. Corneth_'s program for A156552)
%o A364551 isA364551(n) = ((n%2)&&!(n%A005941(n)));
%Y A364551 Cf. A005940, A005941, A156552, A364545, A364549, A364564.
%Y A364551 Subsequence of A364561, which is a subsequence of A364560.
%K A364551 nonn,more
%O A364551 1,2
%A A364551 _Antti Karttunen_, Jul 28 2023