A077760 Numbers which in at least two ways are the product of two distinct numbers with the same digits (leading zeros are forbidden).

101556, 121968, 124012, 133875, 144648, 172900, 185472, 226800, 352170, 433755, 2096640, 3779136, 4264416, 5166504, 5333680, 5448960, 5651919, 5894784, 5955264, 5983936, 6003088, 6174630, 6197724, 6324318, 6351840, 6429600, 6494400, 6514060, 6794424, 6874560, 7064496

Offset: 1

Author

Klaus Brockhaus, Nov 14 2002

Keywords

• nonn
• base

Examples

			101556 = 156*651 = 273*372; 2096640 = 1092*1920 = 1365*1536.
		

Links

• David A. Corneth, Table of n, a(n) for n = 1..10408 (terms <= 2*10^10)

Crossrefs

Cf. A000037, A072443.

Programs

PARI

{for(n=100, 6500000,  my(k=logint(n,100), f=divisors(n), v=[]); for(h=1, matsize(f)[2], if(10^k1, my(w=[]); for(i=1, b, my(s=[], a=v[i]); while(a>0, my(d=divrem(a, 10)); a=d[1]; s=concat(d[2], s)); w=concat(w, [vecsort(s)])); my(c=0); for(i=1, b-1, for(j=i+1, b, if(c<2&&w[i]==w[j], if(v[i]*v[j]==n, if(c==1, print1(n, ", "); c=2, c=1)))))))}

Extensions

Offset changed to 1 by and more terms from David A. Corneth, Sep 08 2024

Name corrected by Sean A. Irvine, Jun 11 2025