A289622 Compound filter (prime signature & Carmichael's lambda): a(n) = P(A046523(n), A002322(n)), where P(n,k) is sequence A000027 used as a pairing function.

1, 3, 5, 14, 12, 27, 23, 44, 40, 42, 57, 90, 80, 61, 42, 187, 138, 148, 173, 117, 61, 111, 255, 324, 257, 142, 308, 148, 408, 558, 467, 773, 111, 216, 142, 856, 668, 259, 142, 375, 822, 625, 905, 222, 265, 357, 1083, 1323, 994, 477, 216, 265, 1380, 844, 306, 430, 259, 534, 1713, 2013, 1832, 601, 148, 3145, 142, 771, 2213, 363, 357

Offset: 1

Author

Antti Karttunen, Jul 16 2017

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000027, A002322, A046523, A286160, A286360, A286573.

Programs

PARI

A002322(n) = lcm(znstar(n)[2]); \\ This function from Charles R Greathouse IV, Aug 04 2012
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ This function from Charles R Greathouse IV, Aug 17 2011
A289622(n) = (1/2)*(2 + ((A046523(n)+A002322(n))^2) - A046523(n) - 3*A002322(n));

Formula

a(n) = (1/2)*(2 + ((A046523(n)+A002322(n))^2) - A046523(n) - 3*A002322(n)).