A064181 Smallest number that can be written in n ways as an unordered sum of 3 nonzero triangular numbers.

0, 3, 12, 30, 61, 52, 82, 136, 142, 147, 192, 277, 247, 367, 552, 457, 516, 507, 646, 637, 721, 822, 787, 1171, 1066, 1137, 1227, 1402, 1192, 1396, 1696, 1501, 1612, 1876, 1927, 1792, 2551, 2587, 2926, 2761, 2422, 2947, 2887, 3262, 3271, 3412, 3937

Offset: 0

Author

Robert G. Wilson v, Sep 20 2001

Keywords

• nonn

Links

• Donovan Johnson, Table of n, a(n) for n = 0..3082

Crossrefs

Cf. A063993.

Programs

Mathematica

a = Table[ n(n + 1)/2, {n, 1, 100} ]; b = {0}; c = Table[ 0, {5000} ]; Do[ b = Append[ b, a[ [ i ] ] + a[ [ j ] ] + a[ [ k ] ] ], {k, 1, 100}, {j, 1, k}, {i, 1, j} ]; b = Delete[ b, 1 ]; b = Sort[ b ]; l = Length[ b ]; Do[ If[ b[ [ n ] ] < 5000, c[ [ b[ [ n ] ] + 1 ] ]++ ], {n, 1, l} ]; Do[ k = 1; While[ c[ [ k ] ] != n, k++ ]; Print[ k - 1 ], {n, 0, 54} ]

Extensions

More terms from Don Reble, Sep 21 2001