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A077760 Nonsquares which in at least two ways are the product of two numbers with the same digits (leading zeros are forbidden). 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Subsequence of A072443.

LINKS

Table of n, a(n) for n=0..25.

EXAMPLE

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

PROG

(PARI) {for(n=100, 6500000, k=floor(log(n)/log(100)); f=divisors(n); v=[]; for(h=1, matsize(f)[2], if(10^k<f[h]&& f[h]<10^(k+1), v=concat(v, f[h]))); b=matsize(v)[2]; if(b>1, w=[]; for(i=1, b, s=[]; a=v[i]; while(a>0, d=divrem(a, 10); a=d[1]; s=concat(d[2], s)); w=concat(w, [vecsort(s)])); 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)))))))}

CROSSREFS

Cf. A072443.

Sequence in context: A229684 A187642 A023077 * A218170 A153050 A203592

Adjacent sequences:  A077757 A077758 A077759 * A077761 A077762 A077763

KEYWORD

base,nonn

AUTHOR

Klaus Brockhaus, Nov 14 2002

STATUS

approved

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Last modified December 12 19:33 EST 2018. Contains 318081 sequences. (Running on oeis4.)