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A116267
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Numbers k such that k*(k+4) gives the concatenation of two numbers m and m-3.
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6
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8, 98, 426, 571, 725, 844, 998, 7808, 9998, 36363, 63634, 99998, 326732, 673265, 999998, 4545452, 5454545, 9999998, 47058821, 52941176, 99999998, 331983805, 332667332, 384615384, 422892896, 475524475, 524475522, 577107101, 615384613, 667332665, 668016192, 719964244
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OFFSET
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1,1
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LINKS
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PROG
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(Python)
from itertools import count, islice
from sympy import sqrt_mod
def A116267_gen(): # generator of terms
for j in count(0):
b = 10**j
a = b*10+1
for k in sorted(sqrt_mod(1, a, all_roots=True)):
if a*(b+3) <= k**2-1 < a*(a+2):
yield k-2
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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