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%I #13 Mar 06 2020 08:10:58
%S 211,215,381,447,602,663,766,807,853,874,1002,1172,1197,1248,1259,
%T 1372,1427,1457,1571,1612,1622,1639,1652,1665,1752,1862,1927,1996,
%U 2047,2152,2245,2297,2302,2332,2351,2415,2472,2497,2506,2523,2618,2887,2912,2952
%N Integers which can be written in exactly two ways as a sum of two distinct nonzero pentagonal numbers.
%e 211 = P(5) + P(11) = P(1) + P(12) = 35 + 176 = 1 + 210, where P(n) is the n-th pentagonal number A000326.
%o (PARI) is(k) = sum(i=1, sqrt(1+12*k)\6, sqrt(1+24*k+12*i-36*i*i)%6==5) == 2; \\ _Jinyuan Wang_, Mar 06 2020
%Y Cf. A000326, A333011, A333013, A333014, A333015.
%K nonn
%O 1,1
%A _Olivier Gérard_, Mar 05 2020
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