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A286450
Restricted growth sequence computed for A252750.
3
1, 1, 2, 3, 4, 5, 6, 3, 2, 7, 8, 1, 9, 10, 11, 12, 7, 13, 14, 5, 15, 16, 17, 14, 18, 19, 20, 21, 22, 23, 24, 12, 25, 1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 1, 5, 56, 31, 57, 58, 59, 7, 60, 61, 62, 17, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81
OFFSET
1,3
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])); }
A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ This function from Michel Marcus
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); t }; \\ Modified from code of M. F. Hasler
A252750(n) = (A003961(A005940(n+1)) - (2 * A005940(n+1)));
write_to_bfile(1, rgs_transform(vector(10000, n, A252750(n))), "b286450.txt");
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 13 2017
STATUS
approved