1,1

The prime factorization of 190911 is 3^1 * 7^1 * 9091^1 with decimal encoding 317190911, which ends in 190911. Hence 190911 is a term of the sequence.

(*returns true if a ends with b, false o.w.*) f[a_, b_] := Module[{c, d, e, g, h, i, r}, r = False; c = ToString[a]; d = ToString[b]; e = StringLength[c]; g = StringPosition[c, d]; h = Length[g]; If[h > 0, i = g[[h]]; If[i[[2]] == e, r = True]]; r]; (*gives the decimal encoding of the prime factorization of n*) g[n_] := FromDigits[Flatten[IntegerDigits[FactorInteger[n]]]]; Do[If[f[g[n], n], Print[n]], {n, 1, 10^6} ]

(PARI) {a067254(a, b) = local(n, v, k, j); for(n=max(2, a), b, v=factor(n); if(eval(concat(vector(matsize(v)[1], k, concat(vector(matsize(v)[2], j, Str(v[k, j]))))))%(10^length(Str(n)))==n, print1(n, ", ")))} a067254(2, 2*10^7)

Cf. A067599.

Adjacent sequences: A067251 A067252 A067253 this_sequence A067255 A067256 A067257

Sequence in context: A023334 A068730 A080050 this_sequence A099806 A050647 A082265

base,nonn

Joseph L. Pe (joseph_l_pe(AT)hotmail.com), Feb 20 2002

Three more terms and PARI code from Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Feb 22 2002