A050810 From sequence A050782, the n's corresponding to the first occurrence of m (or 0 if not defined).

0, 1, 106, 37, 53, 103, 42, 23, 29, 19, 0, 56, 21, 38, 18, 35, 17, 16, 14, 26, 0, 12, 96, 43, 913, 2081, 812, 703, 754, 24, 0, 165, 726, 64, 603, 15, 592, 27, 13, 479, 0, 261, 541, 277, 48, 1129, 437, 649, 524, 538, 0, 291, 406, 1359, 533, 93, 377, 466, 1052, 279, 0

Offset: 0

Author

Patrick De Geest, Oct 15 1999

Keywords

• nonn
• base
• nice

Crossrefs

Cf. A002113, A050782.

Programs

Mathematica

nmax = 60; Clear[f]; f[max_] := f[max] = (r = Reap[For[n = 1, n <= max, n++, k = 1; If[IntegerQ[n/10], m = 0, While[k <= max && Reverse[id = IntegerDigits[k*n]] != id, k++]; m = k]; Sow[{n, m}]]][[2, 1]]; a[0] = 0; a[n_] := (s = Select[r, #[[2]] == n &, 1]; If[s == {}, 0, s[[1, 1]]]); Table[a[n], {n, 0, nmax}]); f[nmax]; f[max = 2 nmax]; While[Print["max = ", max]; f[max] != f[max/2], max = 2 max]; A050810 = f[max] (* Jean-François Alcover, Dec 31 2015 *)