A111634 First occurrence of n in A111633.

1, 11, 13, 14, 15, 16, 17, 18, 19, 25, 205, 1139, 1149, 1159, 26, 206, 1189, 1199, 1259, 36, 27, 207, 1268, 1269, 1274, 1275, 1276, 28, 208, 1279, 1283, 1284, 1285, 1286, 37, 29, 209, 1291, 1293, 1294, 1295, 1296, 1297, 1298, 1299, 2259, 22059, 2368, 2278

Offset

1,2

Comments

A111633: Let n = abc... denote the decimal digits of n. Then a(n) = C(a,z)+C(b,y)+C(c,x)+...+C(x,c)+C(y,b)+C(z,a).

Links

Table of n, a(n) for n=1..49.

Mathematica

f[n_] := Plus @@ Binomial[ IntegerDigits[n], Reverse[ IntegerDigits[ n]]]; Table[ f[n], {n, 0, 100}]; g[n_] := Block[{k = 1}, While[f[k] != n, k++ ]; k]; Table[ g[n], {n, 50}]

Crossrefs

Cf. A111633, A111696.

Sequence in context: A240468 A043645 A043700 * A065877 A290468 A129917

Adjacent sequences: A111631 A111632 A111633 * A111635 A111636 A111637

Keyword

base,nonn

Author

Amarnath Murthy and Robert G. Wilson v, Aug 19 2005

Status

approved