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

0,2

Links

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

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} ]

Crossrefs

Cf. A063993.

Sequence in context: A027480 A135503 A048088 * A281434 A296289 A089143

Adjacent sequences: A064178 A064179 A064180 * A064182 A064183 A064184

Keyword

nonn

Author

Robert G. Wilson v, Sep 20 2001

Extensions

More terms from Don Reble, Sep 21 2001

Status

approved