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A275170
Partition the j digits of n into blocks of k, with 1 <= k <= j-1, starting at right and multiply. Sum of these numbers equals n.
2
369, 1649, 3268, 3924, 6550, 12810, 14472, 25268, 27160, 32650, 38050, 65500, 72712, 100905, 144138, 146016, 146100, 164200, 173070, 210811, 236100, 344200, 655000, 1352045, 1461000, 1642000, 1722240, 2361000, 2701540, 3442000, 4008960, 6161465, 6550000, 14610000
OFFSET
1,1
COMMENTS
Any number of the form 655*10^(k+1), 1461*10^(k+2), 1642*10^(k+2), 2361*10^(k+2), 3442*10^(k+2), with k>=0, belongs to the sequence.
The number of partitions of k digits are [j-(j mod k)]/k. If j is not a multiple of k the last partition has j mod k digits. E.g.: the partitions of 3 digits of 1123885 are 123 and 885 plus a partition of one digit, 1 (here j=7 and k=3). - Paolo P. Lava, Aug 04 2016
LINKS
EXAMPLE
3*6*9 + 3*69 = 369;
1*6*4*9 + 16*49 + 1*649 = 1649;
1*2*8*1*0 + 1*28*10 + 12*810 + 1*2810 = 12810.
MAPLE
P:=proc(q) local a, b, c, k, n; for n from 1 to q do c:=0;
for k from 1 to ilog10(n) do a:=1; b:=n; while b>0 do a:=a*(b mod 10^k); b:=trunc(b/10^k); od;
c:=c+a; od; if n=c then print(n); fi; od; end: P(10^12);
CROSSREFS
Cf. A275171.
Sequence in context: A205730 A251132 A183351 * A205911 A205903 A237844
KEYWORD
nonn,base,easy
AUTHOR
Paolo P. Lava, Jul 19 2016
STATUS
approved