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a(n) is the smallest number k such that A362881(k) = n.
2

%I #60 Dec 19 2024 11:45:36

%S 1,3,6,10,22,31,34,37,40,121,1035,1078,1121,7607,9453,13667,13729,

%T 50040,50123,50206,615964,616448,616932,617416,2828280,2851232,

%U 2874184,2897136,5350614,5583250,5594326,17310256,17312210,17994974,18008820,19051432,19069162

%N a(n) is the smallest number k such that A362881(k) = n.

%C All positive integers will appear in A362881. _Rémy Sigrist_ showed that as a consequence of Van der Waerden's theorem, A362881 is unbounded.

%C The present sequence is monotonically increasing since a progression of length n begins with a progression of length n-1 so a(n-1) < a(n).

%H Kevin Ryde, <a href="/A362909/b362909.txt">Table of n, a(n) for n = 1..62</a>

%H Samuel Harkness, <a href="/A362909/a362909.m.txt">MATLAB program for A362909</a>

%H Kevin Ryde, <a href="/A362909/a362909.c.txt">C Code</a>

%o (MATLAB) See Links section.

%o (C) /* See links */

%Y Cf. A362881.

%K nonn

%O 1,2

%A _Samuel Harkness_, May 14 2023

%E a(25)-a(31) from _Yang Haoran_, May 17 2023

%E a(32)-a(37) from _Kevin Ryde_, May 22 2023