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.
%I A348514 #45 Dec 20 2024 19:12:57 %S A348514 4,10,57,1054,2626,68727,12371554,1673018314,10475647197,11154517557, %T A348514 27594844918,630178495917,7239182861878 %N A348514 Numbers k for which A003961(k) = 2k+1, where A003961 shifts the prime factorization of n one step towards larger primes. %C A348514 Numbers k such that A064216(1+k) = k. %C A348514 It seems that after 4, all other terms are squarefree. See conjecture in A348511. %C A348514 a(9)..a(13) <= 10475647197, 11154517557, 27594844918, 630178495917, 7239182861878, which are also terms. - _David A. Corneth_, Oct 30 2021 %H A348514 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %t A348514 f[p_, e_] := NextPrime[p]^e; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; Select[Range[10^5], s[#] == 2*# + 1 &] (* _Amiram Eldar_, Oct 30 2021 *) %Y A348514 Fixed points of map A108228. (Compare to A048674). %Y A348514 Positions of ones in A252748. %Y A348514 Subsequence of the following sequences: A246282, A319630, A348511, A378980 (see also A379216). %Y A348514 Cf. A000230, A003961, A064216, A326134. %K A348514 nonn,hard,more %O A348514 1,1 %A A348514 _Antti Karttunen_, Oct 29 2021 %E A348514 a(9)-a(11) verified by _Amiram Eldar_, Nov 01 2021 %E A348514 a(12)-a(13) verified by _Martin Ehrenstein_, Nov 08 2021