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A277442 Least number k such that k^2 can be obtained from k by inserting internal (but not necessarily contiguous) digits in n different ways. 2

%I #21 Nov 20 2016 11:28:59

%S 0,10,101,100,10006,950005,1001,9569005,100105,100500,1000,95370001,

%T 1000201,102100005,9957800,100006,9500005,1100005,100100,1010005,

%U 10001,10000096,10005005,1000105,1001005,999578000,1002600005,12500100,100010505,1050500005,1000500

%N Least number k such that k^2 can be obtained from k by inserting internal (but not necessarily contiguous) digits in n different ways.

%C a(6) = 1001.

%H Lars Blomberg, <a href="/A277442/b277442.txt">Table of n, a(n) for n = 0..157</a>

%e a(2) = 101 as 101 is the least number that can be modified in two different ways in order to become its square; i.e., 101^2 equals 10201, which can be represented as 1(02)01 or 10(20)1.

%e a(5) = 950005 because 950005^2 = 902509500025 can be represented in 5 ways: 9(02)5(095)000(2)5, 9(02)50(95)0(0)0(2)5, 9(02)50(95)00(02)5, 9(02)50(950)00(2)5, 9(02509)5000(2)5.

%Y Cf. A046851, A277441.

%K base,nonn

%O 0,2

%A _Ivan N. Ianakiev_, Oct 15 2016

%E Terms a(5), a(7) and beyond from _Lars Blomberg_, Nov 20 2016

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Last modified April 25 05:18 EDT 2024. Contains 371964 sequences. (Running on oeis4.)