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A073582 Numbers k such that S(k) = k/2, where S(k) is the Kempner function A002034. 5

%I #28 Apr 13 2024 14:56:26

%S 6,8,10,14,22,26,34,38,46,58,62,74,82,86,94,106,118,122,134,142,146,

%T 158,166,178,194,202,206,214,218,226,254,262,274,278,298,302,314,326,

%U 334,346,358,362,382,386,394,398,422,446,454,458,466,478,482,502,514

%N Numbers k such that S(k) = k/2, where S(k) is the Kempner function A002034.

%C Unique sequence such that A033677(a(m))-A033676(a(m)) approaches a(m)/2. - Joseph Biberstine, Dec 25 2004

%C Numbers k such that A000203(k) = 3 + k/2 + k. - _Melvin Peralta_, Aug 15 2016

%C Is this sequence "Twice the odd primes and 8"? - _Joerg Arndt_, Sep 13 2016

%H Michel Marcus, <a href="/A073582/b073582.txt">Table of n, a(n) for n = 1..669</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Kempner_function">Kempner function</a>

%t Select[Range@ 514, Function[n, m = 1; While[! Divisible[m!, n], m++]; m == n/2]] (* or *)

%t Select[Range@ 514, DivisorSigma[1, #] == 3 + #/2 + # &] (* _Michael De Vlieger_, Aug 15 2016 *)

%Y Cf. A033676, A033677, A000203.

%K easy,nonn

%O 1,1

%A _Jason Earls_, Aug 28 2002

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Last modified May 7 20:13 EDT 2024. Contains 372317 sequences. (Running on oeis4.)