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!)
 A319500 a(n) is the least m for which A006987(n) = binomial(m,k) for some k, 2 <= k <= m/2. 2
 4, 5, 6, 6, 7, 8, 7, 9, 10, 11, 8, 12, 8, 13, 9, 14, 15, 10, 9, 17, 18, 11, 19, 20, 10, 12, 22, 10, 23, 24, 13, 25, 26, 11, 27, 14, 28, 29, 30, 15, 11, 31, 12, 32, 33, 16, 34, 35, 36, 37, 17, 38, 13, 39, 40, 12, 18, 41, 42, 43, 12, 44, 19, 45, 14, 46, 47, 48, 20, 49, 50, 51, 13, 52, 21, 15, 53 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS First differs from A022911 at n=18. LINKS Robert Israel, Table of n, a(n) for n = 1..10000 FORMULA A006987(n) = binomial(a(n),A318955(n)). EXAMPLE a(3) = 6 because A006987(3) = 15 = binomial(6,2). MAPLE N:= 10000: # for binomial(n, k) values <= N S:= {}: for n from 2 while n*(n-1)/2 <= N do   for k from 2 to n/2 do     v:= binomial(n, k);     if v > N then break fi;     if not member(v, S) then       S:= S union {v};       M[v]:= n;     fi od od: A006987:= sort(convert(S, list)): seq(M[A006987[i]], i=1..nops(A006987)); CROSSREFS Cf. A006987, A022911, A318955. Sequence in context: A225491 A046343 A273227 * A022911 A162310 A116962 Adjacent sequences:  A319497 A319498 A319499 * A319501 A319502 A319503 KEYWORD nonn AUTHOR Robert Israel, Sep 20 2018 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 February 17 12:14 EST 2020. Contains 331996 sequences. (Running on oeis4.)