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.

A240052 2nd arithmetic derivative of products of 2 successive prime numbers (A006094).

Original entry on oeis.org

1, 12, 16, 21, 44, 31, 60, 41, 56, 92, 72, 71, 124, 123, 140, 240, 244, 448, 121, 384, 236, 297, 176, 161, 249, 284, 247, 540, 191, 608, 221, 272, 380, 912, 520, 380, 1024, 371, 428, 912, 852, 508, 1472, 433, 696, 297, 293, 705, 860, 493, 716, 1456, 668, 512, 924, 636, 1188, 552, 669, 764, 2112, 1340, 521, 1504, 951, 1836, 672, 1176, 1300, 1107, 1076, 737, 908, 1520, 641, 776, 661, 821, 1647, 1416, 1828
Offset: 1

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Author

Freimut Marschner, Mar 31 2014

Keywords

Comments

The first arithmetic derivative of products of 2 successive prime numbers (A006094) is the sum of 2 successive prime numbers (A001043). A001043 = (A006094)’. The second arithmetic derivative is a(n)=( A001043)’ = (A006094)’’.

Examples

			(2*3)’ = 1*3+2*1 = 5; (5)’ = 1; (2^2)’ = 2*2^1 = 2*2 = 4.
		

Crossrefs

Cf. A003415 (1st derivative), A068346(2nd derivative).

Programs

  • Haskell
    a240052 = a068346 . a006094  -- Reinhard Zumkeller, Apr 15 2014
  • Maple
    with(numtheory); P:=proc(q) local a,b,c,p,n;
    for n from 1 to q do a:=ithprime(n)*ithprime(n+1);
    b:=a*add(op(2,p)/op(1,p),p=ifactors(a)[2]);
    c:=b*add(op(2,p)/op(1,p),p=ifactors(b)[2]);
    print(c); od; end: P(10^3); # Paolo P. Lava, Apr 01 2014

Formula

a(n) = (A006094(n))''.