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 A114258 Numbers k such that k^2 contains exactly 2 copies of each digit of k. 18
 72576, 406512, 415278, 494462, 603297, 725760, 3279015, 4065120, 4152780, 4651328, 4915278, 4927203, 4944620, 4972826, 4974032, 4985523, 4989323, 5002245, 5016125, 6032970, 6214358, 6415002, 6524235, 7257600, 9883667 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS From Chai Wah Wu, Feb 27 2024: (Start) If k is a term, then k == 0 (mod 9) or k == 2 (mod 9) (see A370676). First decimal digit of each term is 3 or larger. (End) LINKS Chai Wah Wu, Table of n, a(n) for n = 1..10000 (terms 1..645 from Seiichi Manyama) EXAMPLE 72576 is in the sequence since its square 5267275776 contains four 7's, two 2's, two 5's and two 6's. PROG (Python) from math import isqrt from itertools import count, islice def A114258_gen(): # generator of terms for l in count(1): a = isqrt(10**((l<<1)-1)) if (a9:=a%9): a -= a9 for b in range(a, 10**l, 9): for c in (0, 2): k = b+c if sorted(str(k)*2)==sorted(str(k**2)): yield k A114258_list = list(islice(A114258_gen(), 20)) # Chai Wah Wu, Feb 27 2024 CROSSREFS Cf. A114259, A114260, A114261, A199630. Cf. A061656, A061657, A061658, A061659, A061660, A061661, A061662, A061663, A061664. Sequence in context: A183788 A369238 A093212 * A238151 A234243 A260053 Adjacent sequences: A114255 A114256 A114257 * A114259 A114260 A114261 KEYWORD base,nonn AUTHOR Giovanni Resta, Nov 18 2005 STATUS approved

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Last modified April 23 07:42 EDT 2024. Contains 371905 sequences. (Running on oeis4.)