The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A308495 a(n) is the position of the first occurrence of prime(n) in A027748. 2
 2, 3, 5, 8, 13, 16, 22, 25, 32, 41, 45, 55, 62, 66, 73, 83, 94, 98, 109, 117, 120, 132, 138, 150, 166, 173, 177, 185, 188, 196, 224, 231, 243, 247, 267, 271, 284, 295, 303, 315, 327, 331, 353, 356, 364, 368, 394, 419, 426, 430, 439, 452, 456, 475, 487, 500 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Alois P. Heinz, Table of n, a(n) for n = 1..10000 FORMULA A027748(a(n)) = A000040(n). a(n) = 1 + A013939(A000040(n)). - Charlie Neder, Jun 04 2019 a(n) = A082186(A000040(n)). - Alois P. Heinz, Jun 06 2019 EXAMPLE For n = 5: a(5) = 13, A027748(13) = A000040(5) = 11. MAPLE b:= proc(n) option remember; `if`(n=1, 1,       b(n-1) +nops(ifactors(n)[2]))     end: a:= n-> b(ithprime(n)): seq(a(n), n=1..60);  # Alois P. Heinz, Jun 06 2019 MATHEMATICA b[n_] := b[n] = If[n == 1, 1, b[n-1] + PrimeNu[n]]; a[n_] := b[Prime[n]]; Array[a, 60] (* Jean-François Alcover, Nov 27 2020, after Alois P. Heinz *) PROG (Haskell) -- expected to be part of A027748 a027748_list = concat (map a027748_row [1..]) minIdx [] _ = [] minIdx _ [] = [] minIdx (a:as) (b:bs)     | a == b = 1 : (map succ (minIdx as bs))     | otherwise = map succ (minIdx as (b:bs)) a308495_list = minIdx a027748_list a000040_list a308495 n = a308495_list !! (n-1) (PARI) a(n) = 1 + sum(k=1, prime(n), omega(k)); \\ Michel Marcus, Jun 05 2019 CROSSREFS Cf. A000040, A001221, A013939, A027748, A082186. Sequence in context: A076591 A078695 A121367 * A221672 A241551 A070217 Adjacent sequences:  A308492 A308493 A308494 * A308496 A308497 A308498 KEYWORD nonn AUTHOR Peter Dolland, Jun 01 2019 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 15 04:47 EDT 2021. Contains 345043 sequences. (Running on oeis4.)