login
A286533
Restricted growth sequence of A278533 (prime-signature of A253563).
3
1, 2, 3, 2, 4, 5, 3, 2, 6, 7, 7, 5, 4, 5, 3, 2, 8, 9, 10, 7, 9, 11, 7, 5, 6, 7, 7, 5, 4, 5, 3, 2, 12, 13, 14, 9, 14, 15, 10, 7, 13, 15, 15, 11, 9, 11, 7, 5, 8, 9, 10, 7, 9, 11, 7, 5, 6, 7, 7, 5, 4, 5, 3, 2, 16, 17, 18, 13, 19, 20, 14, 9, 18, 21, 21, 15, 14, 15, 10, 7, 17, 20, 21, 15, 20, 22, 15, 11, 13, 15, 15, 11, 9, 11, 7, 5, 12, 13, 14, 9, 14, 15, 10, 7
OFFSET
0,2
LINKS
PROG
(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])); }
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
A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1]))); \\ After M. F. Hasler's code for A006530.
A253550(n) = if(1==n, 1, (n/prime(A061395(n)))*prime(1+A061395(n)));
A253560(n) = if(1==n, 1, (n*prime(A061395(n))));
A253563(n) = if(n<2, (1+n), if(!(n%2), A253560(A253563(n/2)), A253550(A253563((n-1)/2)))); \\ Would be better if memoized!
write_to_bfile(0, rgs_transform(vector(65538, n, A278533(n-1))), "b286533.txt");
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 17 2017
STATUS
approved