Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #19 Sep 17 2023 05:45:21
%S 1,2,3,5,4,6,10,8,9,7,28,15,82,11,12,17,244,18,730,14,30,29,2188,24,
%T 13,83,27,20,6562,21,19684,26,84,245,19,45,59050,731,246,23,177148,33,
%U 531442,32,36,2189,1594324,51,37,16,732,86,4782970,54,31,35,2190,6563,14348908,42,43046722,19685,90,53,85,87,129140164
%N Inverse permutation of A356867, where A356867 is Sycamore's Doudna variant D(3).
%H Rémy Sigrist, <a href="/A365390/b365390.txt">Table of n, a(n) for n = 1..10000</a>
%H Rémy Sigrist, <a href="/A365390/a365390.gp.txt">PARI program</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%F For all n >= 1, A356867(a(n)) = n.
%o (PARI)
%o up_to = 1+(3^15);
%o A365390list(up_to) = { my(v=vector(up_to),met=Map(),h=0,ak); for(i=1,#v,if(1==vecsum(digits(i,3)), v[i] = i; h = i, ak = v[i-h]; forprime(p=2,,if(3!=p && !mapisdefined(met,p*ak), v[i] = p*ak; break))); mapput(met,v[i],i)); my(invs=List([]),x); for(i=1,oo,if(mapisdefined(met,i,&x), listput(invs,x), if(isprime(i)&&i>4, listput(invs, 1+(3^(primepi(i)-2))), return(Vec(invs))))); };
%o v365390 = A365390list(up_to);
%o A365390(n) = v365390[n];
%o for(n=1,#v365390,print1(A365390(n),", "));
%o (PARI) See Links section.
%Y Cf. A365389 (one less), A356867 (inverse), A364958 (fixed points).
%Y Cf. also A005941.
%K nonn
%O 1,2
%A _Antti Karttunen_, Sep 15 2023