A353634 Nondeficient numbers k such that phi(k) = phi(sigma(k)) and A003958(k) = A003958(sigma(k)).

234728, 280904, 461168, 463112, 604136, 742664, 909872, 996008, 1065896, 1191944, 1204424, 1224392, 1465256, 1527656, 1620008, 1757288, 1758536, 1956848, 1985672, 2081768, 2102984, 2358824, 2376296, 2405552, 2518568, 2543528, 2589704, 2670824, 2820584, 2899208, 2912936, 3014024, 3151304, 3196232, 3374696, 3432104

Offset

1,1

Links

Table of n, a(n) for n=1..36.

Index entries for sequences where odd perfect numbers must occur, if they exist at all

Index entries for sequences related to sigma(n)

Prog

(PARI)
A003958(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1]--); factorback(f); };
isA353634(n) = { my(s=sigma(n)); if(s<(2*n), return(0)); ((eulerphi(s)==eulerphi(n)) && (A003958(s)==A003958(n))); };

Crossrefs

Intersection of A023196 and A353635.

Cf. A000010, A000203, A003958, A006872, A062401, A351440, A351442, A351446.

Sequence in context: A202938 A109690 A013905 * A237239 A216056 A258544

Adjacent sequences: A353631 A353632 A353633 * A353635 A353636 A353637

Keyword

nonn

Author

Antti Karttunen, May 04 2022

Status

approved