A340382 Lexicographically earliest infinite sequence such that a(i) = a(j) => A278222(A291759(i)) = A278222(A291759(j)), for all i, j >= 1.

1, 2, 1, 2, 1, 3, 2, 2, 1, 2, 2, 4, 1, 3, 2, 2, 1, 2, 1, 2, 1, 4, 2, 4, 3, 5, 2, 4, 2, 5, 2, 2, 2, 2, 1, 2, 2, 3, 2, 2, 2, 2, 3, 4, 2, 3, 1, 4, 4, 6, 2, 6, 1, 7, 2, 4, 2, 4, 1, 6, 2, 4, 2, 2, 4, 3, 1, 2, 3, 3, 1, 2, 1, 6, 2, 4, 3, 4, 2, 2, 4, 4, 2, 2, 2, 6, 5, 4, 2, 4, 1, 4, 1, 8, 1, 4, 3, 9, 2, 6, 3, 6, 2, 6, 2

Offset: 1

Author

Antti Karttunen, Jan 16 2021

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..65537

Crossrefs

Cf. A278222, A291759, A304748, A340381,

Cf. A340377 (positions of ones).

Cf. also A305302.

Programs

PARI

up_to = 65537;
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From A003961
A048673(n) = (A003961(n)+1)/2;
A289814(n) = { my (d=digits(n, 3)); fromdigits(vector(#d, i, if (d[i]==2, 1, 0)), 2); } \\ From A289814
A291759(n) = A289814(A048673(n));
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
A278222(n) = A046523(A005940(1+n));
rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om,invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om,invec[i],i); outvec[i] = u; u++ )); outvec; };
v340382 = rgs_transform(vector(up_to,n,A278222(A291759(n))));
A340382(n) = v340382[n];