400000000

Appears in sequences

• Powers of 2 written in base 8.at n=26A004647
• Powers of 2 written in base 16.at n=34A004655
• Squares using no more than two distinct digits.at n=34A018885
• Squares with digits in nonincreasing order.at n=36A028822
• Squares such that (1) each digit is a square, (2) the sum of squares of the digits is a square.at n=18A061272
• Squares which produce squares when the leading digit is moved to the end.at n=30A061459
• Smallest n-digit square starting with 4.at n=8A067474
• Expansion of (1-6*x)/(1-10*x).at n=9A093141
• Erroneous version of A052218.at n=16A094628
• Expansion of (1+4x-6x^2-36x^3)/(1-19x^2+90x^4).at n=17A097112
• Coefficient of q^n in (1-q)^5/(1-5q); dimensions of the enveloping algebra of the derived free Lie algebra on 5 letters.at n=13A118266
• Numbers k such that the k-th triangular number contains only digits {0,2,8}.at n=17A119056
• a(3n)=10^n. a(3n+1)=4*10^n. a(3n+2)=7*10^n.at n=25A135262
• Numbers k such that k and k^2 use only the digits 0, 1, 4 and 6.at n=18A136859
• Squares that remain squares when prefixed with a 6.at n=13A167041
• Squares containing only the digits 0, 4 or 8.at n=15A202172
• Squares which have one or more occurrences of exactly two different digits.at n=30A235717
• a(n) = phi(n^9), where phi = A000010.at n=9A239443
• Squares composed of digits {0,2,4}.at n=8A349460
• Perfect squares whose decimal expansion consists of k > 1 digits, k-1 of which are equal.at n=24A368049