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 A262687 a(n) = index of first n in A262680; positions of records in A262680. 4
 0, 1, 4, 169, 324, 1521, 125316, 126025, 425104, 1713481, 1716100, 4959529, 24760576 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS All terms are squares (A262688 gives the square roots). The even and odd terms alternate. LINKS PROG (PARI) allocatemem((2^31)+(2^30)); uplim = 2^25; v262680 = vector(uplim); v262680[1] = 1; v262680[2] = 0; for(i=3, uplim, v262680[i] = issquare(i) + v262680[i-numdiv(i)]; if(!(i%65536), print1(i, ", ")); ); A262680 = n -> if(!n, n, v262680[n]); n=0; k=0; while(n*n <= uplim, if(A262680(n*n)==k, write("b262687.txt", k, " ", n*n); k++); n++; ); (Scheme, with Antti Karttunen's IntSeq-library) (define A262687 (RECORD-POS 0 0 A262680)) CROSSREFS Cf. A262680, A261088, A262514. Cf. A262688 (square roots of these terms). Sequence in context: A024265 A302453 A061710 * A177005 A017414 A051476 Adjacent sequences:  A262684 A262685 A262686 * A262688 A262689 A262690 KEYWORD nonn,more AUTHOR Antti Karttunen, Oct 03 2015 STATUS approved

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Last modified June 25 10:28 EDT 2021. Contains 345453 sequences. (Running on oeis4.)