1,1

So called because 714 is Babe Ruth's lifetime home run record, Hank Aaron's 715th home run broke this record and 714 and 715 have the same sum of prime divisors.

John L. Drost, Ruth/Aaron Pairs, J. Recreational Math. 28 (No. 2), 120-122.

S. G. Krantz, Mathematical Apocrypha, MAA, 2002, see p. 26.

C. Nelson, D. E. Penney and C. Pomerance, "714 and 715", J. Recreational Math. 7 (No. 2) 1974, 87-89.

Science, vol. 275, p. 759, 1997.

P. Weisenhorn, Table of n, a(n) for n=1,..,215

Ivars Petersen, Math. Trek

T. Trotter,Jr., Ruth-Aaron Numbers

T. Trotter,Jr., More information

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Contribution from Weisenhorn Paul (paulweisenhorn(AT)online.de), Jul 02 2009: (Start)

anzahl:=0: n:=4: nr:=0: g:=nops(ifactors(n)[2]):

s[nr]:=sum(ifactors(n)[2, u][1]*ifactors(n)[2, u][2], u=1..g):

for j from n+1 to 1000000 do nr:=(nr+1) mod 2: g:=nops(ifactors(j)[2]):

s[nr]:=sum(ifactors(j)[2, u][1]*ifactors(j)[2, u][2], u=1..g):

if (s[0]=s[1]) then anzahl):=anzahl+1: print(anzahl, j-1, j, s[0]): end if:

end do:

(End)

(Mma program from Harvey P. Dale, Apr 27 2009) ppf[n_] := Plus @@ ((#[[1]] #[[2]]) & /@ FactorInteger[n])

Transpose[Select[Partition[Range[50000], 2, 1], ppf[ #[[1]]]==ppf[ #[[2]]]&]] [[1]]

Cf. A006145, A006146, A039753, A054378.

Sequence in context: A091574 A063731 A129316 this_sequence A141536 A065905 A126695

Adjacent sequences: A039749 A039750 A039751 this_sequence A039753 A039754 A039755

nonn

David W. Wilson (davidwwilson(AT)comcast.net)