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

1,2

Links

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

Formula

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

Prog

(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));

Crossrefs

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

Sequence in context: A227170 A028942 A278314 * A331996 A179213 A074378

Adjacent sequences: A289619 A289620 A289621 * A289623 A289624 A289625

Keyword

nonn

Author

Antti Karttunen, Jul 16 2017

Status

approved