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.

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A385740 Primes p such that there exists a prime q < p such that sigma(p-1) = sigma(q-1) = p + q.

Original entry on oeis.org

1163, 7583, 17099, 48857, 65963, 172859, 5408423, 6804047, 19247087, 73162367, 77695043, 109775657, 109871933, 116464757, 160454717, 175031957, 175288493, 218543393, 268382183, 303220769, 379299989, 705800723, 823155779, 889218389, 967371143, 1100618483, 1242282407, 1701133163
Offset: 1

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Author

S. I. Dimitrov, Jul 08 2025

Keywords

Comments

The primes q and p form a P(-1, -1)-amicable pair. See Dimitrov link.

Examples

			(853, 1163) is such a pair because sigma(853-1) = sigma(1163-1) = 853 + 1163.

Links

Crossrefs

Cf. A000040, A000203, A063990, A008333, A259180, A385586, A385718, A385739.

Extensions

a(6)-a(25) from Michel Marcus, Jul 08 2025
a(26)-a(28) from Giorgos Kalogeropoulos, Jul 14 2025
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Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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