cp's OEIS Frontend

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.

A058198 Where d(m) (number of divisors, A000005) has risen by at least n.

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%I A058198 #25 Jul 02 2025 16:02:00
%S A058198 2,6,12,12,24,24,48,48,60,60,120,120,168,168,180,180,240,240,360,360,
%T A058198 360,360,720,720,720,720,720,720,840,840,1260,1260,1260,1260,1680,
%U A058198 1680,2520,2520,2520,2520,2520,2520,2520,2520,3360,3360,5040,5040,5040,5040
%N A058198 Where d(m) (number of divisors, A000005) has risen by at least n.
%C A058198 a(n) exists for all n (Turán, 1954). - _Amiram Eldar_, Apr 13 2024
%C A058198 a(n) >= A061799(n). - _David A. Corneth_, Apr 13 2024
%D A058198 József Sándor, Dragoslav S. Mitrinovic, and Borislav Crstici, Handbook of Number Theory I, Springer Science & Business Media, 2005, Chapter II, p. 39, section II.1.3.a.
%H A058198 David A. Corneth, <a href="/A058198/b058198.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1004 from T. D. Noe, terms 1005..2044 from Amiram Eldar)
%H A058198 Pál Turán, Problem 71, Matematikai Lapok, Vol. 5 (1954), p. 48, <a href="https://real-j.mtak.hu/9380">entire volume</a>; Solution to Problem 71, by Lajos Takács, ibid., Vol. 56, (1956), p. 154, <a href="https://real-j.mtak.hu/9386">entire volume</a>.
%e A058198 d(11) = 2, d(12) = 6 gives first jump of >= 3, so a(3) = a(4) = 12.
%o A058198 (Haskell)
%o A058198 a058198 = (+ 1) . a058197  -- _Reinhard Zumkeller_, Feb 04 2013
%Y A058198 Equals A058197(n) + 1.
%Y A058198 Cf. A000005, A051950, A058199, A061799.
%K A058198 nonn,nice,easy
%O A058198 1,1
%A A058198 _N. J. A. Sloane_, Nov 28 2000
%E A058198 More terms from _James Sellers_, Nov 29 2000