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A305815
Restricted growth sequence transform of A305814, a filter sequence constructed from the GF(2)[X]-factorization signatures of the divisors of n.
5
1, 2, 2, 3, 4, 5, 2, 6, 7, 8, 2, 9, 2, 5, 6, 10, 11, 12, 2, 13, 14, 5, 15, 16, 3, 5, 17, 9, 15, 16, 2, 18, 5, 19, 20, 21, 2, 5, 22, 23, 2, 24, 15, 9, 25, 26, 2, 27, 7, 9, 28, 9, 15, 29, 14, 16, 22, 26, 2, 30, 2, 5, 9, 31, 32, 33, 2, 34, 20, 35, 15, 36, 2, 5, 37, 9, 5, 38, 15, 39, 40, 5, 41, 42, 43, 26, 5, 16, 15, 44, 45, 46, 5, 5, 8, 47, 2, 12, 48, 49, 41, 50
OFFSET
1,2
FORMULA
For all i, j:
a(i) = a(j) => A000005(i) = A000005(j).
a(i) = a(j) => A294883(i) = A294883(j).
a(i) = a(j) => A294884(i) = A294884(j).
PROG
(PARI)
\\ Needs also code from A305788:
up_to = 65537;
rgs_transform(invec) = { my(occurrences = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(occurrences, invec[i]), my(pp = mapget(occurrences, invec[i])); outvec[i] = outvec[pp] , mapput(occurrences, invec[i], i); outvec[i] = u; u++ )); outvec; };
A305814(n) = { my(m=1); fordiv(n, d, if(d>1, m *= prime(A305788(d)-1))); (m); };
v305815 = rgs_transform(vector(up_to, n, A305814(n)));
A305815(n) = v305815[n];
CROSSREFS
Cf. also A305795.
Sequence in context: A305977 A329048 A167506 * A305789 A344568 A072813
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jun 11 2018
STATUS
approved