Problem 47
prob47 = Flatten[Table[Length[FactorInteger[n]], {n, 1, 200000}]];
prob47b = Table[Sum[prob47[[a + i]], {i, 0, 3}], {a, 1, 199997}];
Position[prob47b, 16]
===========================
Problem 44
prob47b = Table[Sum[prob47[[a + i]], {i, 0, 3}], {a, 1, 199997}];
Position[prob47b, 16]
===========================
Problem 44
prob44a = Table[m*(m + 1)/2, {m, 1, 100000}];
prob44b = Table[n*(3*n - 1)/2, {n, 1, 100000}];
prob44c = Table[o*(2*o - 1), {o, 1, 100000}];
Intersection[prob44a, prob44b, prob44c]
============================
Problem 40
prob44b = Table[n*(3*n - 1)/2, {n, 1, 100000}];
prob44c = Table[o*(2*o - 1), {o, 1, 100000}];
Intersection[prob44a, prob44b, prob44c]
============================
Problem 40
prob40 = Flatten[IntegerDigits[Table[n, {n, 1, 200000}]]];
Product[prob40[[10^a]], {a, 0, 6}]
Product[prob40[[10^a]], {a, 0, 6}]