%I A058854
%S A058854 2,5,7,173,563,73,41,369581,1409,109,449,176459,44221,12148537,148381,
%T A058854 11399977,5779337237,16111,26013917,57405011,3019,1973,191141,6730949,
%U A058854 998917,6619,3853,5153,138961158000728258971,2593,6511107455627473
%N A058854 a(n) = largest prime in the factorization of (n+1)-st Franel number (A000172).
%e A058854 a(3)=173 because the 4-th Franel number is 346 = 2^1 * 173^1, in which
173 is the largest prime.
%p A058854 with(combinat): with(numtheory): A000172 := n->sum(binomial(n,k)^3, k=0..n):
for n from 1 to 50 do printf(`%d,`, ifactors(A000172(n))[2][nops(ifactors(A000172(n))[2])][1])
od:
%t A058854 Do[ Print[ FactorInteger[ Sum[ Binomial[n, k]^3, {k, 0, n}]] [[ -1, 1]]
], {n, 1, 32} ]
%Y A058854 Cf. A000172.
%Y A058854 Sequence in context: A103056 A041445 A041961 this_sequence A006275 A042673
A007571
%Y A058854 Adjacent sequences: A058851 A058852 A058853 this_sequence A058855 A058856
A058857
%K A058854 nonn
%O A058854 0,1
%A A058854 Felix Goldberg (felixg(AT)tx.technion.ac.il), Jan 30 2001
%E A058854 More terms from James A. Sellers (sellersj(AT)math.psu.edu), Feb 01 2001
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