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 A286160 Compound filter: a(n) = T(A000010(n), A046523(n)), where T(n,k) is sequence A000027 used as a pairing function. 18
 1, 2, 5, 12, 14, 23, 27, 59, 42, 40, 65, 109, 90, 61, 86, 261, 152, 142, 189, 179, 148, 115, 275, 473, 273, 148, 318, 265, 434, 674, 495, 1097, 320, 226, 430, 1093, 702, 271, 430, 757, 860, 832, 945, 485, 619, 373, 1127, 1969, 1032, 485, 698, 619, 1430, 838, 1030, 1105, 856, 556, 1769, 2791, 1890, 625, 1117, 4497, 1426, 1196, 2277, 935, 1220 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Antti Karttunen, Table of n, a(n) for n = 1..10000 MathWorld, Pairing Function FORMULA a(n) = (1/2)*(2 + ((A000010(n)+A046523(n))^2) - A000010(n) - 3*A046523(n)). PROG (PARI) A000010(n) = eulerphi(n); A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); };  \\ This function from Charles R Greathouse IV, Aug 17 2011 A286160(n) = (2 + ((A000010(n)+A046523(n))^2) - A000010(n) - 3*A046523(n))/2; for(n=1, 10000, write("b286160.txt", n, " ", A286160(n))); (Scheme) (define (A286160 n) (* (/ 1 2) (+ (expt (+ (A000010 n) (A046523 n)) 2) (- (A000010 n)) (- (* 3 (A046523 n))) 2))) (Python) from sympy import factorint, totient def T(n, m): return ((n + m)**2 - n - 3*m + 2)/2 def P(n):     f = factorint(n)     return sorted([f[i] for i in f]) def a046523(n):     x=1     while True:         if P(n) == P(x): return x         else: x+=1 def a(n): return T(totient(n), a046523(n)) # Indranil Ghosh, May 06 2017 CROSSREFS Cf. A000010, A000027, A046523, A286161, A286162, A286163, A286164. Cf. for example A061468 (one of the sequences this matches with). Sequence in context: A039586 A114217 A286255 * A286163 A286240 A215974 Adjacent sequences:  A286157 A286158 A286159 * A286161 A286162 A286163 KEYWORD nonn AUTHOR Antti Karttunen, May 04 2017 STATUS approved

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Last modified June 18 06:02 EDT 2021. Contains 345098 sequences. (Running on oeis4.)