A351031 a(n) = Product_{d|n, d<n} A019565(A304759(d)).

1, 2, 2, 2, 2, 6, 2, 6, 6, 12, 2, 18, 2, 2, 36, 90, 2, 180, 2, 180, 6, 4, 2, 810, 12, 10, 180, 30, 2, 180, 2, 9450, 12, 20, 12, 56700, 2, 30, 30, 56700, 2, 420, 2, 12, 1080, 10, 2, 1275750, 2, 120, 60, 30, 2, 31500, 24, 9450, 90, 20, 2, 238140, 2, 4, 2520, 10914750, 60, 84, 2, 420, 30, 31500, 2, 2946982500, 2, 6

Offset

1,2

Links

Table of n, a(n) for n=1..74.

Index entries for sequences computed from indices in prime factorization

Prog

(PARI)
A019565(n) = { my(m=1, p=1); while(n>0, p = nextprime(1+p); if(n%2, m *= p); n >>= 1); (m); };
A048673(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); (1+factorback(f))/2; };
A289813(n) = { my(d=digits(n, 3)); fromdigits(vector(#d, i, if (d[i]==1, 1, 0)), 2); } \\ From A289813
A304759(n) = A289813(A048673(n));
A351031(n) = { my(m=1); fordiv(n, d, if(d<n, m *= A019565(A304759(d)))); (m); };

Crossrefs

Cf. A019565, A048673, A289813, A304759, A351030, A351032, A351033 (rgs-transform).

Cf. also A293221.

Sequence in context: A151948 A349923 A080400 * A328236 A119462 A293221

Adjacent sequences: A351028 A351029 A351030 * A351032 A351033 A351034

Keyword

nonn

Author

Antti Karttunen, Jan 29 2022

Status

approved