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!)
 A138296 Table T(k,n) read along antidiagonals: sum of the k-th powers of the distinct prime factors of A024619(n). 1
 5, 13, 7, 35, 29, 5, 97, 133, 13, 9, 275, 641, 35, 53, 8, 793, 3157, 97, 351, 34, 5, 2315, 15689, 275, 2417, 152, 13, 7, 6817, 78253, 793, 16839, 706, 35, 29, 10, 20195, 390881, 2315, 117713, 3368, 97, 133, 58, 13, 60073, 1953637, 6817, 823671, 16354, 275, 641 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Row k=1 is A109353. Rows k=2,3 and 4 are subsequences of A005063-A005065. LINKS J.-M de Koninck, F. Luca, Integers divisible by sums of powers of their prime factors, J. Num. Theory vol 128 (2008) 557-563. FORMULA T(k,n) = sum_{d in A000040, d| A024619(n)} d^k. EXAMPLE Upper left corner of the table starting at row k=1, column n=1: 1|......5.......7.......5.......9.......8.......5.......7. 2|.....13......29......13......53......34......13......29. 3|.....35.....133......35.....351.....152......35.....133. 4|.....97.....641......97....2417.....706......97.....641. 5|....275....3157.....275...16839....3368.....275....3157. 6|....793...15689.....793..117713...16354.....793...15689. 7|...2315...78253....2315..823671...80312....2315...78253. 8|...6817..390881....6817.5765057..397186....6817..390881. MAPLE A024619 := proc(n)     local a;     if n = 1 then         RETURN(6);     else         for a from A024619(n-1)+1 do             if A001221(a) > 1 then                RETURN(a) ;             fi ;         od:     fi ; end: A138296 := proc(n, j)     local f, beta ;     beta := 0 ;     for f in ifactors( A024619(n) )[2] do         beta := beta+op(1, f)^j ;     od:     RETURN(beta) ; end: for d from 1 to 10 do for n from 1 to d do printf("%d, ", A138296(n, d-n+1)) ; od: od: # R. J. Mathar, May 07 2008 CROSSREFS Sequence in context: A094473 A068530 A088315 * A094474 A064109 A175484 Adjacent sequences:  A138293 A138294 A138295 * A138297 A138298 A138299 KEYWORD easy,nonn,tabl AUTHOR R. J. Mathar, May 07 2008 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 5 16:19 EDT 2020. Contains 334852 sequences. (Running on oeis4.)