A286621 Restricted growth sequence computed for filter-sequence A278221, related to the conjugated prime factorization (see A122111).
1, 2, 3, 2, 4, 5, 6, 2, 3, 7, 8, 5, 9, 10, 7, 2, 11, 5, 12, 7, 13, 14, 15, 5, 4, 16, 3, 10, 17, 18, 19, 2, 20, 21, 10, 5, 22, 23, 24, 7, 25, 26, 27, 14, 7, 28, 29, 5, 6, 7, 30, 16, 31, 5, 20, 10, 32, 33, 34, 18, 35, 36, 13, 2, 37, 38, 39, 21, 40, 26, 41, 5, 42, 43, 7, 23, 14, 44, 45, 7, 3, 46, 47, 26, 48, 49, 50, 14, 51, 18, 24, 28, 52, 53, 54, 5, 55, 10, 20, 7
Offset: 1
Keywords
Examples
For n=2, A278221(2) = 2, which has not been encountered before, thus we allot for a(2) the least so far unused number, which is 2, thus a(2) = 2. For n=3, A278221(3) = 4, which has not been encountered before, thus we allot for a(3) the least so far unused number, which is 3, thus a(3) = 3. For n=4, A278221(4) = 2, which was already encountered as A278221(2), thus we set a(4) = a(2) = 2. For n=9, A278221(9) = 4, which was already encountered at n=3, thus a(9) = 3. For n=13, A278221(13) = 64, which has not been encountered before, thus we allot for a(13) the least so far unused number, which is 9, thus a(13) = 9. For n=194, A278221(194) = 50331648, which has not been encountered before, thus we allot for a(194) the least so far unused number, which is 106, thus a(194) = 106. For n=388, A278221(388) = 50331648, which was already encountered at n=194, thus a(388) = a(194) = 106.
Links
- Antti Karttunen, Table of n, a(n) for n = 1..10000
Crossrefs
Programs
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PARI
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; }; write_to_bfile(start_offset,vec,bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); } A064989(n) = {my(f); f = factor(n); if((n>1 && f[1,1]==2), f[1,2] = 0); for (i=1, #f~, f[i,1] = precprime(f[i,1]-1)); factorback(f)}; A122111(n) = if(1==n,n,prime(bigomega(n))*A122111(A064989(n))); A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ This function from Charles R Greathouse IV, Aug 17 2011 A278221(n) = A046523(A122111(n)); write_to_bfile(1,rgs_transform(vector(10000,n,A278221(n))),"b286621.txt");
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