A337194 -id:A337194 - cp's OEIS frontend

A337195 The 2-adic valuation of 1+A000265(sigma(n)), where A000265 gives the odd part.

1, 2, 1, 3, 2, 2, 1, 4, 1, 1, 2, 3, 3, 2, 2, 5, 1, 3, 1, 1, 1, 1, 2, 4, 5, 1, 1, 3, 4, 1, 1, 6, 2, 2, 2, 2, 2, 4, 3, 1, 1, 2, 2, 1, 3, 1, 2, 5, 1, 1, 1, 1, 2, 4, 1, 4, 1, 1, 4, 1, 5, 2, 1, 7, 1, 1, 1, 6, 2, 1, 1, 2, 1, 1, 5, 2, 2, 1, 1, 1, 1, 6, 1, 3, 2, 1, 4, 1, 1, 1, 3, 1, 1, 1, 4, 6, 1, 2, 3, 1, 2, 2, 1, 1, 2

Offset: 1

Antti Karttunen, Aug 18 2020

nonn

Antti Karttunen, Table of n, a(n) for n = 1..65537
Index entries for sequences related to sigma(n)

Cf. A000203, A000265, A007814, A161942, A336698, A337194, A337196.

A007814(n) = valuation(n,2);
A000265(n) = (n>>A007814(n));
A337195(n) = A007814(1+A000265(sigma(n)));

a(n) = A007814(A337194(n)) = A007814(1+A000265(A000203(n))).

A337338 Numerator of (1+sigma(s)) / ((s+1)/2), where s is the square of n prime-shifted once (s = A003961(n)^2 = A003961(n^2)).

Original entry on oeis.org

2, 14, 32, 122, 58, 404, 134, 1094, 782, 742, 184, 3752, 308, 346, 1768, 9842, 382, 10154, 554, 6898, 4124, 2380, 872, 33884, 2802, 3992, 19532, 1238, 994, 22972, 1408, 88574, 5674, 4954, 7582, 94502, 1724, 7190, 9518, 62302, 1894, 53600, 2258, 22144, 44518, 11324, 2864, 305072, 16106, 36414, 11812, 37148, 3542, 253904

Offset: 1

Antti Karttunen, Aug 24 2020

Cf. A003961, A003973, A048673, A336697, A336844, A337194, A337337.

Cf. A337339 (denominators).

A003961(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); };
A337338(n) = { my(s=(A003961(n)^2),t=1+sigma(s)); (t/gcd(t, (s+1)/2)); };
\\ Or as:
A337338(n) = { my(s=A003961(n^2)); numerator((1+sigma(s))/((s+1)/2)); };

a(n) = A337194(A003961(n)^2) / A337337(n).

A337196 The 3-adic valuation of 1+A000265(sigma(n)), where A000265 gives the odd part.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 1

Antti Karttunen, Aug 18 2020

nonn

Antti Karttunen, Table of n, a(n) for n = 1..65537
Index entries for sequences related to sigma(n)

Cf. A000203, A000265, A007949, A074941, A161942, A336698, A336700, A337194, A337195.

Cf. A337197 (the first occurrence of each n).

Array[IntegerExponent[1 + #/2^IntegerExponent[#, 2], 3] &@ DivisorSigma[1, #] &, 105] (* Michael De Vlieger, Feb 22 2021 *)

A007949(n) = valuation(n,3);
A000265(n) = (n>>valuation(n,2));
A337196(n) = A007949(1+A000265(sigma(n)));

a(n) = A007949(A337194(n)) = A007949(1+A000265(A000203(n))).

a(n) = A007949(A336698(n)).

A342466 a(n) = A336466(1+A000265(sigma(n))), where A336466 is fully multiplicative with a(p) = A000265(p-1) for p prime, and A000265(k) is the odd part of k.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 5, 1, 1, 1, 1, 1, 1, 1, 3, 1, 11, 1, 1, 1, 11, 5, 1, 1, 5, 1, 1, 1, 1, 7, 23, 1, 1, 3, 1, 1, 1, 1, 11, 1, 5, 1, 1, 3, 1, 5, 1, 1, 1, 1, 1, 1, 9, 9, 7, 1, 1, 1, 5, 1, 23, 15, 1, 5, 1, 3, 1, 1, 11, 11, 29, 1, 5, 1, 1, 1, 1, 1, 21, 1, 27, 3, 3, 3, 13, 1

Offset: 1

Antti Karttunen, Mar 16 2021

nonn

Index entries for sequences related to sigma(n)

Cf. A000203, A000265, A003958, A161942, A337194, A336466, A336698, A342465.

A000265(n) = (n>>valuation(n,2));
A336466(n) = { my(f=factor(n)); prod(k=1,#f~,if(2==f[k,1],1,(A000265(f[k,1]-1))^f[k,2])); };
A337194(n) = (1+A000265(sigma(n)));
A342466(n) = A336466(A336698(n));

a(n) = A336466(A336698(n)) = A336466(A337194(n)).

a(n) = A000265(A003958(1+A161942(n))).

cp's OEIS Frontend

A337195 The 2-adic valuation of 1+A000265(sigma(n)), where A000265 gives the odd part.

Views

Author

Keywords

Links

Crossrefs

Programs

PARI

Formula

A337338 Numerator of (1+sigma(s)) / ((s+1)/2), where s is the square of n prime-shifted once (s = A003961(n)^2 = A003961(n^2)).

Views

Author

Keywords

Links

Crossrefs

Programs

PARI

Formula

A337196 The 3-adic valuation of 1+A000265(sigma(n)), where A000265 gives the odd part.

Views

Author

Keywords

Links

Crossrefs

Programs

Mathematica

PARI

Formula

A342466 a(n) = A336466(1+A000265(sigma(n))), where A336466 is fully multiplicative with a(p) = A000265(p-1) for p prime, and A000265(k) is the odd part of k.

Views

Author

Keywords

Links

Crossrefs

Programs

PARI

Formula