A115337 a(n) is the smallest number representable in exactly n ways as a sum of 3 palindromes (each of them >= 0).

0, 2, 3, 4, 5, 28, 6, 7, 24, 8, 22, 9, 10, 88, 11, 12, 13, 15, 189, 211, 121, 110, 243, 244, 143, 268, 176, 165, 187, 303, 337, 335, 325, 343, 334, 323, 345, 373, 391, 383, 404, 393, 458, 423, 426, 435, 413, 446, 454, 492, 517, 505, 464, 538, 527, 474, 549, 547

Offset

1,2

Links

Table of n, a(n) for n=1..58.

Example

a(6)=28 since 28 = 22+0+6 = 22+1+5 = 22+2+4 = 22+3+3 = 11+9+8 =
11+11+6 and no number less than 28 has 6 such decompositions.

Mathematica

palQ[n_] := n == FromDigits@Reverse@IntegerDigits@n; pt = Select[Range[0, 10001], palQ]; t = Table[0, {i, 10000}]; Do[v=pt[[i]]+pt[[j]]+pt[[k]]; If[v<10000, t[[v+1]]++ ], {i, 200}, {j, i}, {k, j}]; Table[Position[t, k][[1, 1]]-1, {k, 60}]

Crossrefs

Cf. A115336.

Sequence in context: A124232 A051143 A084853 * A114333 A265098 A076209

Adjacent sequences: A115334 A115335 A115336 * A115338 A115339 A115340

Keyword

base,nonn

Author

Giovanni Resta, Jan 20 2006

Status

approved