A275733 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A275733

a(0) = 1; for n >= 1, a(n) = A275732(n) * A003961(a(A257684(n))).

1, 2, 3, 6, 3, 6, 5, 10, 15, 30, 15, 30, 5, 10, 15, 30, 15, 30, 5, 10, 15, 30, 15, 30, 7, 14, 21, 42, 21, 42, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 7, 14, 21, 42, 21, 42, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 35, 70, 105, 210, 105, 210, 7, 14, 21, 42, 21, 42

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

a(n) = product of primes whose indices are positions of nonzero-digits in factorial base representation of n (see A007623). Here positions are one-based, so that the least significant digit is the position 1, the next least significant the position 2, etc.

LINKS

Antti Karttunen, Table of n, a(n) for n = 0..40320

Indranil Ghosh, Python program for computing this sequence

Index entries for sequences related to factorial base representation

FORMULA

a(0) = 1; for n >= 1, a(n) = A275732(n) * A003961(a(A257684(n))).

Other identities and observations. For all n >= 0:

a(A007489(n)) = A002110(n).

A001221(a(n)) = A001222(a(n)) = A060130(n).

A048675(a(n)) = A275727(n).

A061395(a(n)) = A084558(n).

EXAMPLE