Compound filter (2-adic valuation of phi(n) & sigma(n)): a(n) = P(A053574(n), A000203(n)), where P(n,k) is sequence A000027 used as a pairing function.
A286572
Compound filter (2-adic valuation of phi(n) & sigma(n)): a(n) = P(A053574(n), A000203(n)), where P(n,k) is sequence A000027 used as a pairing function.
Terms
- a(0) =0a(1) =1a(2) =7a(3) =22a(4) =23a(5) =67a(6) =29a(7) =122a(8) =79a(9) =173a(10) =67a(11) =408a(12) =107a(13) =277a(14) =328a(15) =531a(16) =214a(17) =742a(18) =191a(19) =949a(20) =530a(21) =631a(22) =277a(23) =1894a(24) =498a(25) =905a(26) =781a(27) =1598a(28) =467a(29) =2704
External references
- oeis: A286572