A349745 - cp's OEIS frontend

A349745 Numbers k for which k * gcd(sigma(k), A003961(k)) is equal to sigma(k) * gcd(k, A003961(k)), where A003961 shifts the prime factorization one step towards larger primes, and sigma is the sum of divisors function.

n	a(n)
1	1
2	120
3	216
4	672
5	2464
6	22176
7	228480
8	523776
9	640640
10	837760
11	5581440
12	5765760
13	7539840
14	12999168
15	19603584
16	33860736
17	38342304
18	71344000
19	95472000
20	102136320
21	197308800
22	220093440
23	345080736
24	459818240
25	807009280
26	975576960
27	1476304896
28	1510831360
29	1773584640

[1, 120, 216, 672, 2464, 22176, 228480, 523776, 640640, 837760, 5581440, 5765760, 7539840, 12999168, 19603584, 33860736, 38342304, 71344000, 95472000, 102136320, 197308800, 220093440, 345080736, 459818240, 807009280, 975576960, 1476304896, 1510831360, 1773584640]

cp's OEIS Frontend

A349745 Numbers k for which k * gcd(sigma(k), A003961(k)) is equal to sigma(k) * gcd(k, A003961(k)), where A003961 shifts the prime factorization one step towards larger primes, and sigma is the sum of divisors function.

Table of values

List of values