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A281823 Least number k such that (k-n)^2 contains k as a substring. 2
1, 12, 1, 16, 108, 1, 4, 2, 116, 3, 1, 1, 1, 1, 1, 1, 4, 2, 2, 2, 1, 3, 1, 9, 4, 2, 4, 2, 5, 2, 1, 6, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 1, 2, 2, 1, 2, 1, 2, 2, 1, 2, 1, 3, 2, 1, 3, 1, 2, 3, 3, 3, 2, 4, 3, 1, 4, 1, 1, 4, 2, 3, 2, 4, 2, 1, 2, 1, 4, 2, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Paolo P. Lava, Table of n, a(n) for n = 0..10000

EXAMPLE

a(1) = 12 because (12 - 1)^2 = 11^2 = 121 contains 12 as a substring and it is the least number with this property.

MAPLE

with(numtheory): P:= proc(q) local a, b, d, j, k, n, ok;

for n from 0 to q do for k from 1 to q do a:=ilog10(k)+1; b:=(n-k)^2; d:=ilog10((k-n)^2)-ilog10(k)+1;

ok:=0; for j from 1 to d do if k=(b mod 10^a) then ok:=1; break; else b:=trunc(b/10); fi; od;

if ok=1 then print(k); break; fi; od; od; end: P(10^6);

CROSSREFS

Cf. A018834, A281822.

Sequence in context: A070649 A255864 A056583 * A139724 A040155 A036185

Adjacent sequences:  A281820 A281821 A281822 * A281824 A281825 A281826

KEYWORD

nonn,base,easy

AUTHOR

Paolo P. Lava, Jan 31 2017

EXTENSIONS

Typo in definition corrected by Harvey P. Dale, Feb 27 2017.

Entries, Maple code and b-file corrected at the suggestion of Harvey P. Dale, Feb 28 2017.

STATUS

approved

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Last modified July 2 14:41 EDT 2020. Contains 335401 sequences. (Running on oeis4.)