This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A277961 #20 Nov 13 2017 22:01:32 %S A277961 2,12,18,20,21,32,38,48,49,102,120,152,179,180,182,200,201,210,318, %T A277961 320,321,332,338,348,362,380,451,452,462,480,482,490,548,549,649,1002, %U A277961 1012,1020,1021,1049,1102,1111,1188,1200,1201,1429,1488,1498,1518,1520 %N A277961 Numbers n such that 4 is the largest decimal digit of n^2. %C A277961 The actual squares are listed in A277948. - _M. F. Hasler_, Nov 12 2017 %C A277961 Includes 2*10^n+10^m for all n <> m. - _Robert Israel_, Nov 13 2017 %C A277961 For any term of q digits, the first m digits don't exceed (2 * 10^m - 2) / 3 = 666..66 (m 6's) for 1 <= m <= q. - _David A. Corneth_, Nov 13 2017 %C A277961 A term a(n) is in the sequence if and only if a(n)*10^k is in the sequence, for all k >= 0. If a(n) = (x*10^k + y)*10^m with 2xy < 10^k, then (y*10^k+x)*10^m' is also in the sequence, for all m'. - _M. F. Hasler_, Nov 13 2017 %H A277961 Colin Barker, <a href="/A277961/b277961.txt">Table of n, a(n) for n = 1..1000</a> %F A277961 a(n) = sqrt(A277948(n)), where sqrt = A000196 or A000194 or A003059. - _M. F. Hasler_, Nov 12 2017 %p A277961 select(n -> max(convert(n^2,base,10))=4, [$1..10000]); # _Robert Israel_, Nov 13 2017 %o A277961 (PARI) L=List(); for(n=1, 10000, if(vecmax(digits(n^2))==4, listput(L, n))); Vec(L) %Y A277961 Cf. A277948, A277959, A277960. %K A277961 nonn,base %O A277961 1,1 %A A277961 _Colin Barker_, Nov 06 2016