A350620 - OEIS

%I #38 Jan 28 2022 17:42:42

%S 1,7,2,6,71,3,25,5,22,70,30,13,345,24,27,16,161,21,148,69,32,29,51,43,

%T 1154,344,161336,23,34,26,48,737,156,160,36,77534485877,63,147,38,68,

%U 234,31,40,28,53,50,126,42,639,1153,58,343,73,161335,88,111,108,33,135,614667,192,47,65,736,60,155,454,159,186,35,97,77534485876,78,62,2340,146,143,37,24841,67,476,233,433,10579,140,39,359,169,85,52,80,49,195,125,166,41,17282073747557

%N a(n) = smallest k such that A350877(k) = n, or -1 if n does not appear in A350877.

%H Martin Ehrenstein, <a href="/A350620/b350620.txt">Table of n, a(n) for n = 1..126</a>

%Y Cf. A350877. See A350621 for where the primes appear.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Jan 23 2022.

%E a(27) was found by _Keith F. Lynch_, and a(36) and a(72) by _Russ Cox_.

%E a(97) and a(115) were found by _Martin Ehrenstein_ using Kim Walisch's primesieve package.

%E More than the usual number of terms are shown in order to give all the terms up to the extreme value a(97).