cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A344537 Inverse permutation to A344535.

Original entry on oeis.org

0, 1, 2, 4, 8, 3, 64, 5, 16, 9, 1024, 6, 32768, 65, 10, 32, 2097152, 17, 268435456, 12, 66, 1025, 68719476736, 7, 128, 32769, 18, 68, 35184372088832, 11, 36028797018963968, 33, 1026, 2097153, 72, 20, 73786976294838206464, 268435457, 32770, 13
Offset: 1

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Author

Rémy Sigrist, May 23 2021

Keywords

Comments

This sequence is additive.
This sequence establishes a bijection from A225547 to A261195.

Examples

			A344535(42) = 240, so a(240) = 42.
		

Crossrefs

Programs

  • PARI
    a(n) = { my (f=factor(n), v=0); for (k=1, #f~, my (x=primepi(f[k, 1])-1, yy=f[k, 2], y); while (yy, yy-=2^y=valuation(yy, 2); v+=2^(y + (x+y)*(x+y+1)/2))); v }

Formula

a(prime(n)) = A006125(n+1) for any n >= 0.
a(2^2^n) = A036442(n).
A000120(a(n)) = A064547(n).
a(A225546(n)) = A344536(n).
a(n) = A344536(n) iff n belongs to A225547.