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.

Showing 1-2 of 2 results.

A378231 Deficiency of prime-shifted squares: a(n) = 2*A003961(n^2) - sigma(A003961(n^2)), where A003961 is fully multiplicative function with a(prime(i)) = prime(i+1).

Original entry on oeis.org

1, 5, 19, 41, 41, 47, 109, 365, 469, 141, 155, 299, 271, 449, 683, 3281, 341, 1097, 505, 1041, 1927, 663, 811, 2567, 2001, 1211, 11719, 3509, 929, -921, 1331, 29525, 2777, 1545, 4277, 6749, 1639, 2333, 4933, 9141, 1805, 851, 2161, 5235, 16733, 3815, 2755, 22979, 13177, 6805, 6239, 9671, 3421, 27347, 6131, 31049
Offset: 1

Views

Author

Antti Karttunen, Nov 23 2024

Keywords

Comments

See comments in A377879 and in A337339.

Links

Crossrefs

Cf. A000203, A003961, A003973, A033879, A344587, A377879.
Cf. also A337339.

Programs

Formula

a(n) = A344587(n^2) = A377879(A003961(n)).

A378978 Deficiency of even numbers: a(n) = 4*n - sigma(2*n).

Original entry on oeis.org

1, 1, 0, 1, 2, -4, 4, 1, -3, -2, 8, -12, 10, 0, -12, 1, 14, -19, 16, -10, -12, 4, 20, -28, 7, 6, -12, -8, 26, -48, 28, 1, -12, 10, -4, -51, 34, 12, -12, -26, 38, -56, 40, -4, -54, 16, 44, -60, 25, -17, -12, -2, 50, -64, 4, -24, -12, 22, 56, -120, 58, 24, -60, 1, 8, -72, 64, 2, -12, -56, 68, -115, 70, 30, -72, 4, 20
Offset: 1

Views

Author

Antti Karttunen, Dec 13 2024

Keywords

Links

Crossrefs

Even bisection of A033879.
Topmost row of A378979.
Cf. A000203, A033879, A062731.
Cf. also A344587, A377879.

Programs

Formula

a(n) = A033879(2*n) = 4*n - A062731(n).
Showing 1-2 of 2 results.

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