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A336312
Lexicographically earliest infinite sequence such that a(i) = a(j) => A278222(A336120(i)) = A278222(A336120(j)) for all i, j >= 1.
5
1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 3, 1, 2, 1, 2, 1, 3, 2, 2, 1, 2, 1, 3, 1, 4, 1, 2, 2, 2, 1, 2, 1, 3, 1, 3, 1, 2, 1, 2, 1, 4, 1, 2, 1, 2, 1, 4, 2, 3, 1, 2, 1, 2, 1, 2, 1, 4, 2, 3, 1, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 4, 1, 2, 1, 2, 2, 2, 1, 3, 1, 4, 1, 2, 1, 2, 2, 4, 1, 3, 1, 3, 1, 3, 1, 3, 2
OFFSET
1,4
COMMENTS
Restricted growth sequence transform of A278222(A336120(n)).
For all i, j:
a(i) = a(j) => A336121(i) = A336121(j) => A335909(i) = A335909(j).
LINKS
PROG
(PARI)
up_to = 1024; \\ 65537;
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; };
\\ Needs also code from A336124:
A253553(n) = if(n<=2, 1, my(f=factor(n), k=#f~); if(f[k, 2]>1, f[k, 2]--, f[k, 1] = precprime(f[k, 1]-1)); factorback(f));
A336120(n) = if(1==n, 0, (3==A336124(n))+(2*A336120(A253553(n))));
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ From A005940
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));
v336312 = rgs_transform(vector(up_to, n, A278222(A336120(n))));
A336312(n) = v336312[n];
CROSSREFS
Cf. A336119 (positions of ones).
Sequence in context: A161279 A160983 A322354 * A161237 A161061 A161265
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jul 17 2020
STATUS
approved