A293216 a(n) = Product_{d|n, d<n} A260443(d).

1, 2, 2, 6, 2, 36, 2, 30, 12, 108, 2, 2700, 2, 180, 216, 210, 2, 48600, 2, 40500, 360, 1620, 2, 661500, 36, 2700, 1080, 94500, 2, 153090000, 2, 2310, 3240, 3780, 1080, 4465125000, 2, 40500, 5400, 69457500, 2, 34445250000, 2, 21262500, 4082400, 56700, 2, 560290500, 60, 127575000, 7560, 49612500, 2, 1205583750000, 9720, 254677500, 81000, 132300, 2

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..1024

Formula

a(n) = Product_{d|n, d<n} A260443(d).

For all n >= 0, a(2^n) = A002110(n).

For all n >= 1, A007814(a(n)) = A091954(n) and A048675(a(n)) = A001065(n).

Prog

(PARI)
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
A260443(n) = if(n<2, n+1, if(n%2, A260443(n\2)*A260443(n\2+1), A003961(A260443(n\2))));
A293216(n) = { my(m=1); fordiv(n, d, if(d < n, m *= A260443(d))); m; };

Crossrefs

Cf. A048675, A260443, A293217 (restricted growth sequence transform), A293214 (a variant).

Cf. also A001065, A091954.

Sequence in context: A319352 A300834 A293214 * A319708 A230266 A342628

Adjacent sequences: A293213 A293214 A293215 * A293217 A293218 A293219

Keyword

nonn

Author

Antti Karttunen, Oct 03 2017

Status

approved