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A325980
Lexicographically earliest sequence such that a(i) = a(j) => A046523(i) = A046523(j) and A324213(i) = A324213(j) for all i, j.
1
1, 2, 3, 4, 2, 5, 2, 6, 7, 8, 9, 10, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 14, 28, 23, 29, 30, 31, 26, 32, 33, 34, 35, 36, 26, 37, 15, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 35, 50, 53, 54, 50, 55, 56, 57, 38, 58, 45, 59, 45, 60, 61, 62, 63, 64, 45, 65, 66, 67, 68, 69, 60, 70, 71, 72, 68, 73, 49, 74, 75, 76, 71
OFFSET
1,2
COMMENTS
Restricted growth sequence transform of the ordered pair [A046523(n), A324213(n)].
For all i, j: a(i) = a(j) => A325815(i) = A325815(j).
LINKS
PROG
(PARI)
up_to = 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; };
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
A324213(n) = { my(s=sigma(n)); sum(i=0, s, (1==gcd(n-i, n-(s-i)))); };
v325980 = rgs_transform(vector(up_to, n, [A046523(n), A324213(n)]));
A325980(n) = v325980[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 30 2019
STATUS
approved