A304730 Restricted growth sequence transform of A046523(A281978(n)).

1, 2, 3, 4, 3, 4, 3, 5, 4, 6, 7, 6, 5, 8, 2, 6, 5, 9, 10, 11, 9, 12, 5, 6, 7, 13, 14, 15, 16, 17, 16, 15, 14, 18, 19, 20, 13, 21, 13, 22, 20, 23, 24, 23, 22, 25, 26, 27, 28, 29, 28, 27, 19, 26, 20, 22, 18, 22, 13, 21, 11, 30, 31, 32, 33, 34, 35, 36, 37, 38, 31, 39, 2, 8, 5, 9, 5, 6, 7, 16, 6, 17, 16, 31, 12, 40, 8, 31, 12, 31, 11, 30, 31, 39, 16, 17, 16

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..65535

Prog

(PARI)
up_to = (2^16)+1;
v281978 = vector(1+up_to); v281978[1] = 1;
minverses = Map(); mapput(minverses, 1, 1);
least_unused_proper_divisor(inverses, n) = { fordiv(n, d, if((d<n) && !mapisdefined(minverses, d), return(d))); (0); }
prev=1; n = 2; while(n < up_to+1, try = prev; while(mapisdefined(minverses, try) || !(pd = least_unused_proper_divisor(minverses, try)), try += prev); mapput(minverses, v281978[n] = try, n); mapput(minverses, v281978[1+n] = pd, 1+n); prev = pd; n += 2);
A281978(n) = v281978[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; };
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ From A046523
v304730 = rgs_transform(vector(65535, n, A046523(A281978(n))));
A304730(n) = v304730[n];

Crossrefs

Cf. A046523, A281978.

Compare also to the scatter plots of A304098, A304729 and A304732.

Cf. also A304743.

Sequence in context: A165576 A354705 A331730 * A323374 A324197 A259573

Adjacent sequences: A304727 A304728 A304729 * A304731 A304732 A304733

Keyword

nonn

Author

Antti Karttunen, May 19 2018

Status

approved