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 A337784 Smaller of two consecutive oblong numbers which are anagrams of each other. 0
 23256, 530712, 809100, 11692980, 17812620, 20245500, 22834062, 23527350, 29154600, 83768256, 182236500, 189847062, 506227500, 600127506, 992218500, 1363566402, 1640209500, 2175895962, 2422657620, 2477899062, 2520190602, 3041687952, 3764129256, 4760103042 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are multiples of 9. The indices of these oblong numbers are 152, 728, 899, 3419, 4220, 4499, 4778, 4850, 5399, 9152, 13499, 13778, 22499, 24497, 31499, 36926, 40499, 46646, 49220, 49778, 50201, 55151, 61352, 68993. LINKS EXAMPLE 530712 is in the sequence because it is an oblong number, 530712 = 728 * 729, and the next oblong number, 532170 = 729 * 730, is an anagram of 530712. MATHEMATICA s = {}; o1 = 1; d1 = Sort @ IntegerDigits[o1]; Do[o2 = n*(n + 1); d2 = Sort @ IntegerDigits[o2]; If[d2 == d1, AppendTo[s, o1]]; o1 = o2; d1 = d2, {n, 2, 70000}]; s (* Amiram Eldar, Sep 21 2020 *) PROG (PARI) ok(k) = {my(b, m=0); if(issquare(4*k + 1), b=truncate(sqrt(4*k + 1) - 1)/2; if(vecsort(digits(k)) == vecsort(digits((b + 1)*(b + 2))), m = 1)); m} CROSSREFS Subsequence of A008591. Cf. A002378, A069567, A227692, A228133, A228135. Sequence in context: A205176 A205275 A133968 * A333746 A251111 A205834 Adjacent sequences: A337781 A337782 A337783 * A337785 A337786 A337787 KEYWORD nonn,base AUTHOR Antonio Roldán, Sep 21 2020 STATUS approved

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Last modified March 22 06:17 EDT 2023. Contains 361413 sequences. (Running on oeis4.)