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 A277200 Even terms in A260442 (in A260443). 5
 2, 6, 18, 30, 90, 210, 270, 450, 630, 2310, 6750, 6930, 9450, 15750, 20250, 22050, 30030, 47250, 90090, 330750, 510510, 727650, 1212750, 1531530, 1653750, 2668050, 3543750, 4961250, 8489250, 9699690, 18191250, 24806250, 25467750, 29099070, 40020750, 53156250, 57881250, 104053950, 173423250, 173643750 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All odd terms larger > 1 in A260442 can be obtained from these terms by shifting their prime factorization some number of steps towards larger primes with A003961. LINKS Table of n, a(n) for n=1..40. PROG (PARI) allocatemem(2^30); A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1]))); \\ After M. F. Hasler's code for A006530. A048675(n) = my(f = factor(n)); sum(k=1, #f~, f[k, 2]*2^primepi(f[k, 1]))/2; \\ Michel Marcus, Oct 10 2016 A003961(n) = my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); \\ From Michel Marcus A260443(n) = if(n<2, n+1, if(n%2, A260443(n\2)*A260443(n\2+1), A003961(A260443(n\2)))); isA277200(n) = (!(n%2) && (omega(n) == A061395(n)) && (A260443(A048675(n)) == n)); i=1; n=0; while(i < 100, n++; if(isA277200(n), write("b277200.txt", i, " ", n); i++)); CROSSREFS Cf. A003961, A260442, A260443. Sequence A277324 sorted into ascending order. Subsequence of A055932. Cf. A002110, A277317 (subsequences, apart from their initial terms). Also all terms of A277318 apart from initial 3 are included in this sequence. Sequence in context: A351875 A197168 A288815 * A277324 A034881 A352813 Adjacent sequences: A277197 A277198 A277199 * A277201 A277202 A277203 KEYWORD nonn AUTHOR Antti Karttunen, Oct 14 2016 STATUS approved

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Last modified May 18 03:12 EDT 2024. Contains 372617 sequences. (Running on oeis4.)